Abraham Lincoln relieves General Ambrose Burnside [US} from command of the Army of the Potomac, replacing him with General Joseph "Fighting Joe" Hooker.
General "Fighting Joe" Hooker's Army of the Potomac is defeated by Robert E. Lee's Army of Northern Virginia as it crosses the Rappahannock on the way to Richmond
General Robert E. Lee [CS] advances into Pennsylvania where he meets George Meade [US]. First battling north of the city, by the second day Union forces had retreated south, forming a strong line as men arrived almost continuously. On the third day, the infamous Pickett's Charge marked the end of the Confederates hope for a victory
John Pemberton, commander of Confederate forces at Vicksburg asks Ulysses S. Grant for terms. Grant demands an unconditional surrender. Pemberton refuses. Late in the evening, Grant offers excellent terms and Pemberton accepts.
General Braxton Bragg [CS] tries to split General William Rosecrans [US] forces as they try to return to the safety of Chattanooga. A second day breakthrough at the Brotherton Cabin forces the federals into a retreat, halted only by the Rock of Chickamauga, General George Thomas on Snodgrass Hill
The bloodiest two days in American history cost the Federals 1,657 dead, 9,756 wounded, and 4,757 missing for a total of 16,170 casualties out of 58,000 troops. The Confederate losses were 2,312 dead, 14,674 wounded and 1,468 for a total of 18,545 out of 66,000 troops.
At the dedication of the National Cemetery in Gettysburg President Lincoln delivers a two-minute speech. Immediately following the speech he calls it a "flat failure." The speech is known today as the Gettysburg Address
Three Union armies attacked the Army of Tennessee atop Missionary Ridge, east of downtown Chattanooga. Patrick Cleburne stopped William Tecumseh Sherman from the north, although outnumbered 10 to 1. Joe Hooker was seriously delayed by burnt bridges and failed to hit the southern end of Bragg's line near Rossville, Georgia. Thomas' Army of the Cumberland struck the center, breaking Bragg's line and forcing a retreat. Sheridan, ordered to pursue, was stopped dead in his tracks by William Hardee's rear guard action.