John D. Felmley was born around 1825 in Pennsylvania to John W. Felmley. He married Violet Anderson, and they had at least six children: James, born around 1848; Anderson, born around 1851; David, born around 1853; John, born around 1855; Theodore, born around 1856; and Moses, born around 1860. They lived in Shelocta, Pennsylvania, and he worked as a miller. By 1860, he owned $400 of real estate and $250 of personal property.
He enlisted in the Union army on February 23, 1864, and mustered in as a commissary sergeant in Company B of the 14th Pennsylvania Cavalry later that day. He mustered out in Fort Leavenworth, Kansas, on August 24, 1865.
Felmley applied for a federal pension in November 1897, claiming that he “los[t] the power of smelling.” By 1880, they were living in Gilead, Illinois, and Felmley was working as a farmer. They moved to King County, Washington, sometime in the 1880s. His wife died in the late 1800s, and by 1900, he was living with his son David in Rome, Washington. He died in Van Wyck, Washington, on March 17, 1908.