(1813–64) Union army officer. The Connecticut native fought in Mexican War (1846–48). In 1855 he left the artillery for the newly organized First Cavalry and fought the Indians in the plains. He considered leaving the military but changed his mind at the outbreak of the Civil War;he was promoted to lieutenant colonel of the Second Cavalry in 1861 and later returned to command his old unit. He was a protégé of Gen. George B. McClellan, whom he repaid with steadfast loyalty. Sedgwick fought with distinction in the Peninsular campaign of 1862 but led his troops into disaster at Antietam that same year, suffering 2,200 casualties in twenty minutes. He fought to victory in a secondary battle at Fredericksburg (1863) while Gen. Joseph Hooker fought the main engagement at Chancellorsville, but Sedgwick's indecisive action afterward allowed the Confederates to achieve victory. In pursuit of Gen. Robert E. Lee's troops after Gettysburg (1863), Sedgwick again was tentative in his actions. He was killed in action at Spotsylvania.
From The Oxford Essential Dictionary of the U.S. Military in Oxford Reference.
Subjects: Warfare and Defence.