Josiah Gregg, 1806–50, American trader and historian of the Santa Fe Trail, b. Overton co., Tenn. He moved with his family to Illinois (1809) and then to Missouri (1812). He gained wide knowledge from his diverse readings. He journeyed to Santa Fe for the first time in 1831 and later, having become a trader, made many expeditions, sometimes going as far as Chihuahua, Mexico. He recorded his observations, which were published as Commerce of the Prairies (1844, new ed. 1954), later regarded as a classic of American frontier history and literature. He served under Gen. John W. Wool in the Mexican War and 1849 joined the California gold rush. He died when leading a prospecting party across the Coast Range in the winter.
See his diary and letters, ed. by M. G. Fulton (1941–44).