Thomas Crook Sullivan (November 14, 1833 – March 11, 1908) was a brigadier general in the United States Army. Sullivan was born at Montgomery County, Ohio, the son of Samuel Sullivan, the proprietor of Sullivan's Tavern, the brother of Ohio 2nd Dist Appellate Judge Theodore Sullivan, and the nephew of future Major General George Crook via older sister Maria Crook Sullivan. He graduated from West Point in 1856, ranking twelfth in a class of forty-nine. His first assignment was as a second lieutenant in the First U.S. Artillery serving on the Texas frontier and during this period was with the expedition against Juan Cortina's Mexican marauders, seeing combat near Fort Brown, Texas. He was later ordered to Washington City (DC), arriving in the Winter of 1861, and selected as a guard for presi