Joseph D. Wyman was born around 1825 in Maine. He married a woman named Mary, and their daughter Ada was born around 1854. They lived in Freeport, Maine, and Wyman worked as a farm laborer. By 1860, he owned $250 of real estate and $100 of personal property.
He enlisted in the Union army on December 10, 1861, and he mustered in as a private in Company E of the 13th Maine Infantry later that day. The regiment was stationed along the Gulf Coast for the next few years. He chose not to reenlist, explaining in February 1864 that he “love[d] my home to much to enlisted for three years longer. I wood not stay three [more] years for all unkle Sam bounty. I love my wife and daughter dear.” He assured his daughter that he would return in “nine month[s]…if noething hapuns.” Wyman died of “acute diarrhea” in Washington, D.C., July 29, 1864. His body was exhumed on November 26, 1864, and reburied in Arlington National Cemetery.