Thomas Fidler was born around 1834 in England. He eventually immigrated to America, and he settled in Providence, Rhode Island. He married a woman named Mary, and they had at least two children: Wilhelmina, born around 1861; and James, born around 1869.
He enlisted in the Union army on August 30, 1861, and he mustered in as a sergeant in Battery G of the 3rd Rhode Island Heavy Artillery. The regiment took part in the siege of Charleston. He mustered out on October 5, 1864.
He returned to Providence after the war, and he earned a living as a blacksmith. He died sometime in the late 1800s.