Charles Hargin was born around 1842 in Tompkins County, New York, to Mark Jefferson Hargin. His father was a farm laborer, and his mother probably died sometime before 1850. Hargin attended school in Tompkins County, and he enlisted in the Union army on August 30, 1862. He mustered in as a private in Company F of the 9th New York Heavy Artillery. The regiment took part in the Overland Campaign, the Shenandoah Valley Campaign, the Siege of Petersburg, and the Appomattox Campaign. He mustered out on May 14, 1865, in Baltimore, Maryland. Hargin returned to Tompkins County after the war, and he was working as a farm laborer in 1865. He married Anne Drake around 1866, and their son Mark was born soon afterward. The couple divorced sometime in the 1870s. He died sometime after 1880.