Osprey Order of Battle 2 : Gettysburg July 1 1863 : Union : The Army of the Potomac

The encounter near the quiet hamlet of Gettysburg determined the choice of ground on which the success or failure of Lee's 1863 invasion of the North would be decided. Hour-by-hour battle accounts, enlivened by tales of individual acts of courage, tell of command decisions that committed the I and XI Corps to a forward defence of the terrain north and west of Gettysburg in an effort to delay the Confederate convergence on the strategic crossroads. These decisions led to staggering losses and ultimate retreat. Nightfall on July 1st found the Confederates enjoying a tactical victory. But stubborn Federal resistance had allowed the Union forces to regroup on the commanding terrain south of Gettysburg. The accomplishments of the Federal I and XI Corps emboldened General George Meade to hold the ground and offer battle. No one knew that two more days of desperate conflict lay ahead. Text by James Arnold and Roberta Wiener.