The 1st Delaware Infantry Regiment, later known as the 1st Delaware Veteran Infantry Regiment was a United States volunteer infantry regiment raised for Union Army service in the American Civil War. Part of the II Corps it served in the Eastern Theater of the American Civil War.

Thomas Alfred Smyth was a brigadier general in the Union Army during the American Civil War. He was the last Union general killed in the war. In March 1867, he was nominated and confirmed a brevet major general of volunteers posthumously to rank from April 7, 1865.