Sioux Wars defeated a force of 1,300 Americans under General George Crook. Crook retreated which helped lead to the infamous Battle of Little Big Horn beginning on June 25. Lieutenant Colonel George Custer, commanding a force of over 600 troops, was badly defeated with the loss of over 300 men killed or wounded, including himself. The next major engagement occurred at Slim Buttes on September 9 and 10. While moving toward Deadwood to secure supplies for Crook's command, elements of the 1st Cavalry commander by Capt Anson Mills located and attacked a Sioux village. The Dull Knife Fight, on November 25, and
George Armstrong Custer during the Manassas Campaign, where Army commander Winfield Scott detailed him to carry messages to Major General Irvin McDowell. After the battle, Custer continued participating in the defenses of Washington D.C. until October, when he became ill. He was absent from his unit until February 1862. In March, he participated with the 2nd Cavalry in the Peninsula Campaign (March to August) in Virginia until April 4. On April 5, Custer served in the 5th Cavalry Regiment and participated in the Siege of Yorktown, from April 5 to May 4 and was aide to Major General George B. McClellan; McClellan was