Constantine Samuel Rafinesque (1783-1840) was a botanist and professor. Originally born in Turkey, he came to Philadelphia in 1802. He met Thomas Jefferson in July 1804 while traveling through Maryland, Virginia and the District of Columbia to study the local flora. Although this was their only meeting, they corresponded sporadically for the next twenty years.
During their first bout of correspondence, Rafinesque expressed keen interest in the Lewis and Clark Expedition. Jefferson suggested that he might prove useful in a proposed expedition along the Red River. Rafinesque did not join this expedition, having left the country for Italy before receiving the letter. He remained there for the next ten years.
Rafinesque returned to the U.S. in 1815, and accepted a position as a botany professor at Transylvania University in 1819. Rafinesque wrote to Jefferson after a silence of nearly fifteen years to inquire after a professorship at the University of Virginia. Jefferson promised to "lay [his] letter before the board in due time." Rafinesque was ultimately unsuccessful in securing a position at the new university, despite applying to Jefferson several more times over the next few years.
Rafinesque remained at Transylvania University and did extensive archaeological and linguistic work on the early people in the Ohio Valley. In 1826, he moved to Philadelphia where he continued to write until his death by cancer.