In 1861 Wild enlisted in the First Massachusetts Infantry. He was quickly promoted to captain. He was present at First Manassas but only engaged at Blackburn's Ford. In the Peninsula Campaign, Wild was wounded at Seven Pines. He mustered out only to muster back into the 35th Massachusetts Infantry, which he led at South Mountain. He was commissioned in April 1863 as a brigadier general. In his recovery, Wild recruited African American troops, to be known as "Wild's African Brigade." His brigade manned Fort Pocahontas in North Carolina during the attack at Wilson's Wharf in May 1864. Later, they were called to action at Cold Harbor and at Richmond at the end of the war.
