What was Nicholas Trist's occupation during the Mexican-American War?

During the Mexican-American War, Nicholas Trist served as a diplomat and a chief clerk in the U.S. State Department. He was tasked with negotiating peace terms with Mexico and played a key role in the Treaty of Guadalupe Hidalgo, which ended the war and ceded significant territory to the United States. Trist's efforts were crucial in shaping the post-war border and expanding U.S. territory.