Daniel Sickles, one of the most competent yet controversial of Civil War generals, studied law at New York University and was active in Democratic politics, serving in the U.S. Congress 1857-61. He achieved public notice when, in 1859, he caught his wife with another man. Sickles, enraged, shot and killed the man, who happened to be the son of Francis Scott Key. He was, however, acquitted on the grounds that his actions were in defense of his home and family.
In September 1861, Sickles became a brigadier general of volunteers, a reward for his support of Abraham Lincoln's war policy and for raising a brigade of soldiers in New York. On November 29, 1862, he was promoted to major general and given command of a division, which he commanded in the Peninsula Campaign, at Antietam, and at Fredericksburg. Given command of the III Corps at Chancellorsville, Sickles was given the duty of pursuing Maj. Gen. Thomas J. "Stonewall" Jackson's command, which was mistakenly believed to be retreating. The gap left in Union lines by the absence of two-thirds of Sickles' command contributed to the success of Jackson's flanking march, which won the battle for the Confederates.
One of the Civil War's most acrimonious controversies stemmed from Sickles' actions at Gettysburg. The III Corps was ordered to cover the Union left near the Round Tops. Sickles, on his own initiative, advanced his corps to an exposed position that bore the brunt of Lt. Gen. James Longstreet's assault. In the fierce fighting that followed, Sickles was severely wounded in the right leg. Because of his mistake, Sickles would lose not only his leg but his command, along with some of his reputation. During the course of his long life he blamed Maj. Gen. George Meade for the unfortunate results of his ill-considered advances, and would also charge Meade with incompetence as an army commander, though he had nothing to back up his claim.
In 1869 Sickles retired as a major general in the Regular Army, then filled various public offices, including U.S. minister to Spain from 1869-75, and U.S. congressman from 1893-95. He died May 3, 1914, in New York City.
Sickles was a capable leader, and possessed great courage; even his mistake at Gettysburg could have been excused had he not made a public debate of his differences with Meade. His affinity for controversy with his fellow officers and his combative attitude toward his superiors detracted from an otherwise admirable military record.