The Battle of Williamsburg, fought on 5 May 1862, was the first major engagement of the Peninsula Campaign. Union Maj. Gen. Georg B. McClellan, slowly advancing from Hampton Roads toward Richmond, encountered the rear guard of Confederate Gen. Joseph E. Johnston's westward-moving army near here. Confederates under Maj. Gen. James Longstreet delayed the Union advance in a fierce, daylong battle in a driving rain. Nearly 41,000 Federals and 32,000 Confederates were engaged, with about 4,000 casualties. The result was a draw, although both sides claimed victory. The next day, the Confederates continued marching toward Richmond and Union troops occupied Williamsburg.