During the American Civil War, Hamilton sided with the Union. During this time he went on a tour of the Northeast, giving speeches in New York, Boston, and other northern cities. He spoke out in favor of the Union and criticized the "slave power" of the South. Because of this Hamilton was regarded as a hero in the North, though he was generally viewed as a traitor at home. President Abraham Lincoln named Hamilton the Military Governor of Texas in late 1862. He spent most of the war serving in this position in New Orleans, after an attempt to capture South Texas failed in 1863.
