The Battle of Williamsburg, Va., is the first major combat of Union Gen. George B. McClellans Virginia Peninsula Campaign.
Waged May 4-5, 1862, the battle pitted nearly 41,000 Union soldiers against more than 30,000 Confederate forces. Union forces advancing after a Confederate retreat from Yorktown clashed with a Confederate rearguard near Williamsburg but were nearly pushed back in attacking Confederates hunkered down behind strong earthworks.
At one point, the Union force appeared close to being repelled before arriving reinforcements shore up their position. The fighting raged on before Confederate forces pulled back at the battles end in a nighttime move.
The battle comes as a cautious McClellan, despite tens of thousands of troops, tentatively begins pressing toward Richmond up the peninsula formed by the York and James Rivers. More than 3,800 casualties are estimated at Williamsburg, heavily to the Union side.
By May 6, Union forces continue probing toward Richmond, capital of the Confederacy, and a day later theres a smaller fight of a Union division with two Confederate brigades.