William Starke Rosecrans (September 6, 1819 – March 11, 1898) was an inventor, coal-oil company executive, diplomat, politician, and United States Army officer. He gained fame for his role as a Union general during the American Civil War. He was the victor at prominent Western Theater battles, but his military career was effectively ended following his disastrous defeat at the Battle of Chickamauga in 1863.