nearly two to one
So terrible had been the depression following Chancellorsville , so rapid the desertions , so numerous the leaves of absence , that the combined forces of the Army of the Potomac with the State troops under the new call reached only this pitiful total . Lee 's swift column penetrated almost to the gates of Harrisburg before Meade 's advance division of twenty-five thousand men had caught up with his rear at Gettysburg on July 1st . Seeing that a battle was inevitable , Lee drew in his advance lines and made ready for the clash . The Northern army was going into this fight with the smallest number of men relatively which he had ever met -- though outnumbering him nearly two to one . The difference was that here the North was defending her own soil . It was not surprising that on the eve of such a battle in the light of the frightful experiences of the past two years that Washington should be in a condition of panic . A single defeat now with Lee 's victorious army north of the Capital meant its fall , the inevitable dismemberment of the Union , and the bankruptcy and ruin of the remaining Northern States .