 Complete the following phrase:  Part of Sickles Excelsior Brigade, the 72nd New York participated in many of the wars most significant battles. Transported to Washington, D.C., the members of this regiment were initially attached to Division of the Potomac Sickles Brigade, and assigned to defend the city before participating in the Union Armys expedition to lower Maryland September 15October 2, 1861. They were then reassigned as Sickles Brigade to the U.S. Army of the Potomac in October as part of the division commanded by Brigadier-General Joseph Hooker. Their next significant deployment came as part of the U.S. Armys Third Corps, Second Division when they engaged in the Union Armys advance on Manassas, Virginia March 10, 1862, the expedition from Dumfries to Fredericksburg, capture of stores March 18, and reconnoissance from Liverpool Point to Stafford Court House and subsequent operations there April 4. Reassigned to the Peninsula Campaign, they then participated in the Siege of Yorktown, Virginia April 5May 4, 1862, and incurred heavy casualties in the Battle of Williamsburg May 5. By the time that battle was over, nearly 200 members of the regiment had been killed or wounded, a loss rate which the regiment would not experience again for the remainder of the war. Next engaged in the a hrefBattle20of20Seven20PinesBattle of Seven PinesFair Oaksa May 31June 1, the regiment then fought in the Seven Days Battles at Oak Grove June 25, the Peach Orchard and Savages Station June 29, 