Lee at the Battle of Chancellorsville in Hooker had served in the Seminole Wars and the Mexican—American War , receiving three brevet promotions, before resigning from the Army. At the start of the Civil War, he joined the Union side as a brigadier general, distinguishing himself at Williamsburg , Antietam and Fredericksburg , after which he was given command of the Army of the Potomac.
His ambitious plan for Chancellorsville was thwarted by Lee's bold move in dividing his army and routing a Union corps, as well as by mistakes on the part of Hooker's subordinate generals and his own loss of nerve.
The defeat handed Lee the initiative, which allowed him to travel north to Gettysburg. Hooker was kept in command, but when General Halleck and Lincoln declined his request for reinforcements, he resigned.
George G. Meade was appointed to command the Army of the Potomac three days before Gettysburg. Hooker returned to combat in November , helping to relieve the besieged Union Army at Chattanooga, Tennessee , and continuing in the Western Theater under Maj. William T. Sherman , but departed in protest before the end of the Atlanta Campaign when he was passed over for promotion. Hooker became known as "Fighting Joe" following a journalist's clerical error; however, the nickname stuck. His personal reputation was as a hard-drinking ladies' man, and his headquarters were known for parties and gambling.
Hooker was born in Hadley, Massachusetts , the grandson of a captain in the American Revolutionary War. He was of entirely English ancestry, all of which had been in New England since the early s. He graduated from the United States Military Academy in , ranked 29th out of a class of 50, and was commissioned a second lieutenant in the 1st U.
