Ulrich Päßler

Plantae des États-Unis

Rediscovered Pages from Alexander von Humboldt’s
United States Diary


Ein jüngst im Nachlass Alexander von Humboldts aufgefundenes Manuskript enthält Aufzeichnungen über seinen Aufenthalt in den USA im Jahr 1804. Auf nur vier Seiten finden sich Notizen über Gespräche mit Präsident Thomas Jefferson und dem Botaniker G. H. E. Mühlenberg, Angaben über Nutz- und Heilpflanzen, eine Auflistung nordamerikanischer Naturforscher sowie Informationen über Verbraucherpreise.


A recently discovered manuscript sheds a new light on Alexander von Humboldt’s stay in the USA in 1804. The document contains his notes on conversations with President Thomas Jefferson and botanist G. H. E. Mühlenberg. Humboldt also collected information on useful and medicinal plants, listed North American naturalists and documented consumer prices.


Un manuscrit découvert récemment jette un nouvel éclairage sur le séjour d’Alexander von Humboldt aux États-Unis en 1804. Le document contient ses notes sur des conversations avec le président Thomas Jefferson et le botaniste G. H. E. Mühlenberg, des informations sur les plantes utiles et médicinales, une liste de naturalistes nord-américains et des informations sur des prix à la consommation.

Introduction – Humboldt’s travel diaries

The complexities that Alexander von Humboldt’s American travel diaries pose for the researcher have been pointed out repeatedly: The journals do not consist of a simple day by day account of incidents and observations. As a traveler’s notebook, they also contain lists of statistical data, geophysical measurements and schematic pictorial representations, as well as discrete scholarly tracts in preparation of future publications.1 This complex arrangement of information does not constitute field notes in the literal sense of the expression. Following a long-established travelers’ practice of note-taking, Humboldt jotted down impressions immediately, on the move. In due course, he transferred these notes into notebooks, where they could take form of travelogues or revised data lists.2 Humboldt discarded many, though certainly not all, of his actual field notes, once he had incorporated the desired pieces of information into his notebooks. Some records and sketches (especially preparatory drawings for maps) were never assigned to booklets, but rather kept separately. What is more, Humboldt, who made use of his American notes and notebooks for research purposes up until his old age, kept on rearranging these manuscripts and even circulated them among colleagues and assistants.

These paper practices, implemented during and after the voyage, make it almost impossible to define a genuine, precisely confined “canon” of Humboldt’s travel diaries. Single folios, often just short memos and drawings on small pieces of paper taken during the journey, can be found throughout his papers. To be sure, Humboldt himself created a corpus between 1853 and 1855, when he finally had his American notebooks bound into nine volumes.3 But at least two lengthy passages that described the route from Mexico to Veracruz and his sojourn on the island of Cuba in 1804 were omitted or simply forgotten when assembling the volumes. These two missing manuscripts have been identified among Humboldt’s papers in the early 2000s.4 Humboldt’s account of a six-week stopover in the United States of America and the crossing from Philadelphia to Bordeaux, however, remains to be discovered.

Humboldt in the US – in his own words

Alexander von Humboldt’s visit to the United States from 20 May to 30 June 1804 has been subject to a few detailed depictions.5 In the context of this short article, a rough outline of his stay therefore may suffice. Humboldt, his travel companions Aimé Bonpland and Carlos de Montúfar (who had joined the two in Quito in 1802) arrived in Philadelphia from Cuba on 20 May. From there, they travelled to Washington D. C., arriving on 1 June, where Humboldt met, among others, President Thomas Jefferson. On their way back to Philadelphia, the three travelers made a detour to Lancaster, Pennsylvania. Here Humboldt, Bonpland and Montúfar met botanist Gotthilf Heinrich Ernst Mühlenberg (or Muhlenberg) on 16 June. They returned to Philadelphia on 18 June, where they set sail for Bordeaux on 30 June.

Recently four pages have emerged among Humboldt’s papers kept in the Berlin State Library that contain notes taken by Humboldt on conversations with Jefferson and Mühlenberg, as well as observations of the nature in the states of Pennsylvania, Delaware, Maryland and Virginia (Fig. 1).6 This manuscript, entitled by Humboldt in Latin and French “Plantae des États-Unis”, was probably written in June 1804, before setting sail to Europe. Bearing the above-mentioned travelers’ note-taking practices in mind, it seems fair to assume that Humboldt copied and re-assembled on these page details from notes that he had jotted down in passing while visiting Washington and Lancaster.


Fig. 1: First page of Humboldt’s manuscript “Plantae des États-Unis”. Staatsbibliothek zu Berlin – Preußischer Kulturbesitz (SBB PK), Handschriftenabteilung, Nachlass Alexander von Humboldt, gr. Kasten 6, Nr. 81a, fol. 11r. (CC BY-NC-SA 3.0 Deutschland, http://creativecommons.org/licenses/by-nc-sa/3.0/de/)

This fragment of Humboldt’s diary was found amongst an array of handwritten documents dealing with plant geography and botanical arithmetic mostly written during the 1820s. The token “Ag”, which was subsequently inserted on the upper right-hand side of the first page, refers to the significance of the sheets for Humboldt’s later work: Around 1825, the fragment had become part of a collection of documents that he and his assistant Karl Sigismund Kunth compiled for a second edition of the Ideen zu einer Geographie der Pflanzen (Humboldt 1807); the tokens helped to group documents for the future publication.7 The manuscript contains information on North American plant species, their distribution limits and similarity to European species that was supposed to be included in the book.

Synopsis of the manuscript

The document consists of two large folios, each folded lengthwise. Humboldt wrote on only four of the eight pages. The first three pages contain 12 consecutively numbered segments; the numbering is missing from three paragraphs written on the last page.

The title of these pages “Plantae des États-Unis” already points out their central subject. They contain mainly information on useful plants and timber of the United States. In the first five segments, Humboldt notes particulars on medical plants and plants used for dyeing and tanning, including source references for some of the information. Here, he most probably wrote down information which he had gathered during conversations with botanist G. H. E. Mühlenberg in Lancaster. In fact, Humboldt explicitly mentions Mühlenberg in the next two subtopics 6 and 7 that refer to North American oak species: “Muhlenberg believes that there could exist 28 species [of oak trees, UP]. Mr. Kin claims to have 50 of them.”8

The passage Humboldt labeled as number 7 might be the most interesting part of this manuscript. Here Humboldt gathers facts and opinions stated by Mühlenberg and Thomas Jefferson in conversations with him on the use of American oak trees for ship-building, for which mainly the species Quercus vivens, Quercus alba and Quercus prinus were used. Humboldt, who had visited the Washington Navy Yard on 4 June 1804, remarked: “The US Navy in its current state has frigates that rot very quickly, especially where the wood is too thick and air does not circulate.”9

While Thomas Jefferson linked the poor quality of the oak wood to trees grown in the North, whose species were presumably native to southern regions, Mühlenberg disagrees:

Monsieur Muhlenberg denies the fact and assures us that his Quercus castanea, bicolor and alba are as good as the species of Europe, but that one must take them from enclosed places, not to use them green or too young, to dry them before using them, to remove the bark well. Too little attention is paid when choosing them and there are few old trees.10

Here, Humboldt inserts his own observation on the age of the oak trees he saw during his trip through four states. He attributes the relative youth of the forest to fire clearing as allegedly practiced by the first nations:

Indeed, we saw few [trees] with more than 18–20 inches in diameter in Pennsylvania, Delaware, Maryland and Virginia, because white men have only been masters of this country for 100–120 years and the hunter Indians used to burn the forests to see more clearly there.11

While topics 8, 10 and 11 once more return to the subject of medical plants and the distribution of North American plant species, item 9 constitutes a list of eighteen North American botanists and gardeners. Some are still well-known today, such as the explorer William Bartram, the physician Benjamin Smith Barton or the gentleman gardener William Hamilton.12 Particularly noticeable are the names of numerous naturalists of German descent, pastors and teachers belonging to the Moravian church, as well as church Lutheran ministers (such as G. H. E. Mühlenberg himself). One of Mühlenberg’s students, Pastor Johann Daniel Kurtz in Baltimore, is mentioned under topic 12 along with his colleague Frederick Valentine Melsheimer in Hanover, Pennsylvania as collectors of entomological and mineralogical specimens.13 Again, it is likely that Humboldt had received information on these American naturalists from Mühlenberg, who exchanged letters and specimens with them.14

The content of the last page of the manuscript seems more eclectic than the previous ones. First, Humboldt reports on the exhibition of an American bison in Washington D. C. two years prior to his visit: “A buffalo was exhibited in Washington in 1802 which weighed 3100 pounds. It stood 19 ½ hands (of 4 inches) tall and was 25 feet long from nose to tail. Canada”15

The description of this enormous specimen can be interpreted in connection with 18th-century philosophical debates on the “New World”: Authors like Cornelis de Pauw and Guillaume-Thomas Raynal claimed the feebleness of America’s nature and its inhabitants, a point of view that Humboldt would strongly contest in his travel accounts.16

In the following paragraph, Humboldt once more refers to his encounter with Thomas Jefferson in Washington. Here, we learn that Humboldt had compared Jefferson’s vocabulary lists of Indian languages of North America with his own notes taken in South America: “Among the 23 Indian languages that Monsieur Jefferson is going to publish, I only found the word run of the Unquachog language which means man in it as in Ynga of Peru.”17

The next to last paragraph, the only section written in German, contains information on prices for accommodation, provision, transportation and clothing in Philadelphia and Washington. Among other things, Humboldt compares the price of a bottle of porter beer consumed in an inn, with its price in town (half a dollar vs. quarter of a dollar), and names the price for attire consisting of jacket, trousers and vest (30 dollars).18

A final observation is made of the geological formations of the region around Lancaster, which is, according to Humboldt, dominated by mica and chlorite schist.19


The surprising site where this document has been found – namely, as part of a collection of botanical manuscripts written in the 1820s – does not only give yet another proof of Humboldt’s practice of re-using and re-arranging of notes taken during his voyage. It also shows that further fragments of the lost United States diary could be found in unexpected places among the Humboldt papers deposited in Berlin and Kraków. In fact, another manuscript from Humboldt’s hand has surfaced recently among his meteorological and climatological data collection containing excerpts from Andrew Ellicott’s published travel diary (Ellicott 1803) and suppositions by the Philadelphia physician Caspar Wistar on epidemic diseases – Humboldt had met both men while in the United States.20 Additional investigations are still needed to verify that this document actually constitutes a fragment of the travel notes. At all events, it shows that a further exploration of Humboldt’s papers is definitely worthwhile.


Boedeker, Hans Erich (2002): “‚Sehen, hören, sammeln und schreiben‘. Gelehrte Reisen im Kommunikationssystem der Gelehrtenrepublik.” In: Paedagogica Historica. International Journal of the History of Education, 504–513.

Bourguet, Marie-Noëlle (2010): “A Portable World: The Notebooks of European Travellers (Eighteenth to Nineteenth Centuries).” In: Intellectual History Review 20, 377–400.

Casper, Gerhard (2011): “A Young Man from ‘ultima Thule’ Visits Jefferson: Alexander von Humboldt in Philadelphia and Washington.” In: Proceedings of the American Philosophical Society 155, 247–262.

Erdmann, Dominik/Jutta Weber: “Nachlassgeschichten – Bemerkungen zu Humboldts nachgelassenen Papieren in der Berliner Staatsbibliothek und der Biblioteka Jagiellońska Krakau.” In: HiN – Alexander von Humboldt im Netz. Internationale Zeitschrift für Humboldt-Studien XVI, 31, 58–77. URL: http://dx.doi.org/10.18443/223 (Date accessed: October 6, 2017).

Ellicott, Andrew (1803): The journal of Andrew Ellicott, late commissioner on behalf of the United States during part of the year 1796, the years 1797, 1798, 1799, and part of the year 1800: for determining the boundary between the United States and the possessions of His Catholic Majesty in America, containing occasional remarks on the situation, soil, rivers, natural productions, and diseases of the different countries on the Ohio, Mississippi, and Gulf of Mexico, with six maps. Philadelphia: Thomas Dobson.

Ette, Ottmar (2012): “Archeologies of Globalization. European Reflections on two Phases of Accelerated Globalization in Cornelius de Pauw, Georg Forster, Guillaume-Thomas Raynal and Alexander von Humboldt.” In: Culture & History Digital Journal 1.1. URL: http://dx.doi.org/10.3989/chdj.2012.003 (Date accessed: October 6, 2017).

Faak, Margot/Christian Suckow (2000): “Einleitung”. In: Alexander von Humboldt: Reise durch Venezuela. Auswahl aus den amerikanischen Reisetagebüchern. Edited by Margot Faak (Beiträge zur Alexander-von-Humboldt-Forschung, 12). Berlin: Akademie Verlag, 11–31.

Friis, Herman R. (1959): “Alexander von Humboldts Besuch in den Vereinigten Staaten von Amerika vom 20. Mai bis zum 30. Juni 1804”. In: Alexander von Humboldt. Studien zu seiner universalen Geisteshaltung. Edited by Joachim H. Schultze. Berlin: De Gruyter, 142–195.

Friis, Herman R. (1960): “Baron Alexander von Humboldt’s Visit to Washington, D. C., June 1 through June 13, 1804.” In: Records of the Columbia Historical Society 60/62, 1–35.

Humboldt, Alexander von (1804): “Ag – Plantae des États-Unis”. Edited by Ulrich Päßler in collaboration with Ingo Schwarz. In: edition humboldt digital. Edited by Ottmar Ette. Berlin-Brandenburgische Akademie der Wissenschaften, Berlin. Version 2, September 14, 2017. URL: http://edition-humboldt.de/v2/H0006939 (Date accessed: October 6, 2017).

Humboldt, Alexander von (1807): Ideen zu einer Geographie der Pflanzen nebst einem Naturgemälde der Tropenländer, Auf Beobachtungen und Messungen gegründet, welche vom 10ten Grade nördlicher bis zum 10ten Grade südlicher Breite, in den Jahren 1799, 1800, 1801, 1802 und 1803 angestellt worden sind, von Al. Von Humboldt und A. Bonpland. Bearbeitet und herausgegeben vom dem Erstern. Mit einer Kupfertafel. Tübingen, Paris: Cotta.

Humboldt, Alexander von (2004): Alexander von Humboldt und die Vereinigten Staaten von Amerika. Briefwechsel. Edited by Ingo Schwarz (Beiträge zur Alexander-von-Humboldt-Forschung; 19). Berlin: Akademie Verlag.

Humboldt, Alexander von (2005): Von Mexiko-Stadt nach Veracruz. Tagebuch. Edited by Ulrike Leitner (Beiträge zur Alexander-von-Humboldt-Forschung; 25). Berlin: Akademie Verlag.

Humboldt, Alexander von (2016): “Isle de Cube. Antilles en général.” Edited by Ulrike Leitner, Piotr Tylus and Michael Zeuske in collaboration with Tobias Kraft. In: edition humboldt digital. Edited by Ottmar Ette. Berlin-Brandenburgische Akademie der Wissenschaften, Berlin. Version 2, September 14, 2017. URL: http://edition-humboldt.de/v2/H0002922 (Date accessed: October 6, 2017).

Jefferson, Thomas (1791): “VIII. Jefferson’s Vocabulary of the Unquachog Indians”, [14 June 1791]. In: Founders Online, National Archives, last modified June 29, 2017. [Original source: The Papers of Thomas Jefferson, vol. 20, 1 April–4 August 1791, ed. Julian P. Boyd. Princeton: Princeton University Press, 1982, 467–470.] URL: http://founders.archives.gov/documents/Jefferson/01–20-02–0173-0009 (Date accessed: October 6, 2017).

Päßler, Ulrich (2017): “Dokumente zu einer Neuausgabe der Geographie der Pflanzen – Einführung.” In: edition humboldt digital. Edited by Ottmar Ette. Berlin-Brandenburgische Akademie der Wissenschaften, Berlin. Version 2, September 14, 2017. URL: http://edition-humboldt.de/v2/H0016420 (Date accessed: October 6, 2017).

Rebok, Sandra (2014): Humboldt and Jefferson. A Transatlantic Friendship of the Enlightenment. Charlottesville, London: University of Virginia Press.

Schönhofer, Matthias (2014): Letters from an American Botanist: The Correspondences of Gotthilf Heinrich Ernst Mühlenberg (1753–1815) (Beiträge zur Europäischen Überseegeschichte; 101). Stuttgart: Franz Steiner.

Schwarz, Ingo (2004): “Einführung.” In: Humboldt 2004, 11–65.

Wulf, Andrea (2011): Founding Gardeners. The Revolutionary Generation, Nature, and the Shaping of the American Nation. New York: Alfred A. Knopf.

1 For a concise characterization of the journals and their contents see Faak/Suckow 2000, 17–19.

2 For an overview of European travelers’ notation techniques around 1800 see Bourguet 2010. On the particular practice of taking draft notes in the field see ibid., 384–388 and Boedeker 2002, 513.

3 Erdmann/Weber 2015, 67.

4 These manuscripts were edited in 2005 and 2016 (Humboldt 2005; Humboldt 2016).

5 In 1959, the American archivist Herman R. Friis published the most comprehensive study on Humboldt’s US American itinerary and encounters to date (Friis 1959). The English version published one year later focuses on Humboldt’s stay in Washington D.C. (Friis 1960). More recent accounts (Schwarz 2004, 11–14; Casper 2011; Rebok 2014, 20–31) are largely based on Friis 1959, but offer widened biographical insights into Humboldt’s favorable and hopeful views on the early republic and his friendship with Thomas Jefferson. Humboldt 2004, 87–104 contains a complete edition of Humboldt’s correspondence during his trip to the US.

6 Staatsbibliothek zu Berlin – Preußischer Kulturbesitz (SBB PK), Handschriftenabteilung, Nachlass Alexander von Humboldt, gr. Kasten 6, Nr. 81a, fol. 11r–14v. A complete transcription of the document as well as facsimiles can be found here: http://edition-humboldt.de/v2/H0006939 (Humboldt 1804).

7 There are at least 25 more documents in Humboldt’s papers bearing similar tokens. On this collection of documents and the projected, yet never published second edition of Humboldt 1807 see Päßler 2017.

8 “Muhlenberg croit qu’il peut y avoir dans les États-Unis 28 espèces. Monsieur Kin prétend en avoir 50.” SBB PK, Handschriftenabteilung, Nachlass Alexander von Humboldt, gr. Kasten 6, Nr. 81a, fol. 11r. Humboldt refers twice to the German-American plant collector Matthias Kin in the manuscript. It is yet to be determined if they met in person.

9 “La Marine des États-Unis dans son État actuel a des frégates qui pourrissent très vite surtout où le bois est trop épais où l’air n’y circule pas.” Ibid., fol. 11v.

10 Ibid.

11 “En effet, nous en vîmes peu au-delà de 18–20 pouces de diamètre en Pensylvanie, Delaware, Maryland et Virginie, car les hommes blancs ne sont maîtres de ce pays que depuis 100–120 ans et les Indiens chasseurs avaient coutume de brûler les forêts pour y voir plus clair.” Ibid.

12 On the role of botanists, agriculturalists and gardeners in shaping the early American republic’s identity as a self-sufficient nation of natural abundance see Wulf 2011. On W. Bartram, B. S. Barton and W. Hamilton in particular see ibid., 43; 72–78; 158–159.

13 Ibid., fol. 12r.

14 On Mühlenberg’s extensive North American as well as transatlantic network of correspondents cf. Schönhofer 2014.

15 “On a fait voir en 1802 à Washington un buffalo qui pesait 3100 livres, il avait 19 ½ hands (à 4 pouces) de haut et 25 piés de long du nez à la queue. Canada.” SBB PK, Handschriftenabteilung, Nachlass Alexander von Humboldt, gr. Kasten 6, Nr. 81a, fol. 13v.

16 See Ette 2012.

17 “Parmi les 23 langues Indiennes que Monsieur Jefferson va publier, je n’ai trouvé que le mot run de la langue Unquachog qui y signifie homme comme en Ynga du Pérou.” SBB PK, Handschriftenabteilung, Nachlass Alexander von Humboldt, gr. Kasten 6, Nr. 81a, fol. 13v. Humboldt refers to a vocabulary of the Unquachog Indians, compiled by Jefferson: https://founders.archives.gov/documents/Jefferson/01–20-02–0173-0009 (Jefferson 1791).

18 “bouteille Porter im Inn ½ dollar, in Stadt ¼ dollar. Ein Glas Limonade ¼ dollar.” “Kleid, Hosen und Weste 30. dollar.“ Ibid. According to https://www.measuringworth.com $ 0.50 in real price of 1804 would be about $ 10.50 today. Accordingly, $ 30 would equal about $ 629.

19 Ibid.

20 Extrait de “Journal of Andrew Ellicott”, SBB PK, Handschriftenabteilung, Nachlass Alexander von Humboldt, gr. Kasten 5; Nr. 42, Bl. 1–4: http://resolver.staatsbibliothek-berlin.de/SBB00019E2200000000. Humboldt misspells “Wistar” as “Whister”. Ibid., fol. 3v.

Copyright (c) 2017 Ulrich Päßler

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