1. Julius Philipp Benjamin von Rohr (c.1735–1793) was a native of Prussia, but he spent most of life in service to the Danish government, which in 1757 appointed him municipal buildings inspector and government land surveyor of the Danish West Indies, the present-day U. S. Virgin Islands. An avid botanist, Rohr established a botanical garden on Santa Cruz (Saint Croix), and in the 1780s the Danish government commissioned him to study the cultivation of cotton in the Caribbean and South America. He published his results as Anmerkungen über den Cattunbau zum Nuzen der dänischen westindischen Colonien (Altona and Leipzig, 1791–93). His visit to the United States preceded a scientific expedition sponsored by the Danish government to conduct botanical studies on the Guinea Coast of West Africa. Rohr’s ship from New York City was lost at sea on its voyage to Africa.

2. Ernest Frederick von Walterstorff (1755–1820) served as governor-general of Santa Cruz 1787–94 and 1802–3. For an abstract of his letter to Jefferson of 9 Oct. 1792, in which he introduced Rohr and enclosed part 1 of the botanist’s cotton study, see Jefferson Papers, description begins Julian P. Boyd et al., eds. The Papers of Thomas Jefferson. 41 vols. to date. Princeton, N.J., 1950–. description ends 24:458.