The Army of the Potomac’s (AOP’s) primary mission was the defense of Washington, D.C. Click on map to enlarge. Lee’s army (in red) occupied the Rappahannock’s right bank.
Often inaccurately depicted as a “Winter Encampment,” the AOP’s winter of 1863 was a strategic pause in which the army occupied a 200-square-mile, gourd-shaped defensive perimeter. Fully-manned infantry and cavalry picket lines, shown here (in green) on February 25, 1863, extended south-north from the Rappahannock to Dumfries in Prince William County, and west-east from Hartwood in Stafford into King George County. The defenses protected central camps of seven infantry and one cavalry corps (100 miles in circumference). Note the camps were oriented in defensive directions on the perimeter.