The size of the forces engaged at Gettysburg was Approximately 100,000 total.

The conflict saw approximately 93,921 Union troops from the Army of the Potomac, under the command of General George Meade, face off against around 71,699 Confederate soldiers from the Army of Northern Virginia, led by General Robert E. Lee. This pivotal engagement unfolded over three days, from July 1 to July 3, 1863, and was marked by intense combat that resulted in significant casualties for both sides. The magnitude of the battle highlighted its critical role as a turning point in the Civil War.