Homer Baxter Sprague (October 19, 1829 - March 23, 1918) was an American author, educator, abolitionist, and Lieutenant Colonel of the Union Army. A native of Sutton, Massachusetts, Sprague was a Captain of the 13th Connecticut Infantry Regiment in 1861 when the American Civil War began, and quickly rose to the rank of Colonel before being captured as a prisoner of war by the Confederate Army in 1864. In 1865 he was released in a prisoner exchange, and remained active within the military until the end of the war.