Milton Powers was born in Orange, Vermont, on February 18, 1831, to Jonathan and Elizabeth Powers. His mother died when he was two years old, and he was raised by his grandfather and aunt. In the early 1840s, he began working in a meat market in Pittsfield, Massachusetts, and he remained in the beef industry until the Civil War began.
He enlisted in the Union army in Pittsfield on October 7, 1861, and he mustered in as a sergeant in the 11th United States Infantry. The regimen took part in the Peninsula campaign, the Seven Days' Battles, the Second Battle of Manassas, the Battle of Antietam, the Battle of Fredericksburg, the Battle of Chancellorsville, the Battle of Gettysburg, and the Overland Campaign. During the Battle of the Wilderness in May 1864, his horse was shelled out from under him, and Powers was knocked unconscious. He mustered out on October 7, 1864.
In 1864, he married Ellen D. Mowry, the daughter of his former employer. They had at least two children: Mattie and Avery. The family moved to Whitingham, Vermont, in 1866 and then to Halifax, Vermont, around 1883. He was one of the charter members of the Charles P. Clark Post of the Grand Army of the Republic. According to one local writer, Powers was also active in local political and business affairs. He applied for a federal pension in September 1881 and eventually received one. He died in Halifax on January 14, 1889.