The battle began when Confederate soldiers led by A.P. Hill encountered attacks from the Union led by John Buford. By the first day, 90,000 Union troops lead by George Meade against 75,000 Confederates by general Lee. On the second day, Northern troops took over but had to give up some land. On the third day, the gave more land. It was 23,000 Union and 28,000 Confederate killed or wounded. Over 30% of casualties. Northerners were enthusiastic about breaking the charm of Lee's invincibility.