| 1863 | June 3 | Gettysburg Campaign begins with the movement of the Army of Northern Virginia. |
| 1863 | June 9 | Battle of Brandy Station. |
| 1863 | June 13 | Battle of Winchester. |
| 1863 | June 17 | Battle of Aldie. |
| 1863 | June 17 | Battle of Middleburg (June 17-19). |
| 1863 | June 21 | Battle of Upperville. |
| 1863 | June 23 | The Army of Northern Virginia begins crossing the Potomac River into Maryland, from Harper's Ferry, on their way to Pennsylvania. |
| 1863 | June 26 | Skirmish near Gettysburg. |
| 1863 | June 27 | George Gordon Meade is appointed commander of the Army of the Potomac, supplanting Joe Hooker. |
| 1863 | June 28 | Confederate forces under Jubal Early capture York, Pennsylvania. |
| 1863 | June 28 | Judson Kilpatrick named commander, 3rd Division, Cavalry Corps, Army of the Potomac. |
| 1863 | June 30 | Battle of Hanover. |
| 1863 | July 1 | Battle of Gettysburg (July 1-3). |
| 1863 | July 2 | Confederate General William Barksdale killed at Gettysburg. |
| 1863 | July 3 | Richard Brooke Garnett, Confederate General, is killed in action at Gettysburg, Pennsylvania. |
| 1863 | July 3 | Elon John Farnsworth, Union General, is killed in action at the Battle of Gettysburg, Pennsylvania. |
| 1863 | July 3 | Action at Fairfield. |
| 1863 | July 4 | Lee and the Army of Northern Virginia begin their retreat from Gettysburg back to Virginia. |
| 1863 | July 5 | Lewis Addison Armistead, Confederate General, dies in Pennsylvania from wounds received at Gettysburg. |
| 1863 | July 8 | Battle of Boonsboro. |
| 1863 | July 23 | Battle of Manassas Gap. |
| 1863 | November 19 | President Abraham Lincoln delivers The Gettysburg Address. |