1863 map of Battle of Gettysburg on July 1-3, 1863.Union and Confederate positions are shown along with artillery. Confederate Corps are named and Union forces are named and shown in more detail. Union General Hooker was relieved By General George Meade prior to Gettysburg. Robert E. Lee’s forces had invaded the North to draw the Union army away from Richmond, but Lee was defeated and forced to retreat back to the South.