Francis Carpenter Miller was born on December 22, 1839, in Tombs Run, Pennsylvania, to David Robert Miller and Mary Campbell. His father was a blacksmith who owned $200 of real estate in 1850. Miller grew up and attended school in Lycoming County, Pennsylvania.
He enlisted in the Union army on September 7, 1861, and mustered in as a corporal in Company A of the 50th New York Engineers later that day. The regiment took part in the Battle of Fair Oaks, the Seven Days' Battles, and the Battle of Fredericksburg. Miller spent most of 1863 and 1864 stationed in Washington, D.C., and he was eventually promoted to sergeant. He expressed devotion to the Union, explaining that he fought "in the defence of the stars and stripes which I hope long may wave over the land of the free and the home of the brave." He mustered out in Elmira, New York, on September 20, 1864, when his term of enlistment expired.
Miller returned to Pennsylvania after the war, and he married Agnes Voris in April 1865. They had at least five children: Hiram, born around 1867; Catherine, born around 1870; Reuben, born around 1871; Anna, born around 1876; and Marian, born around 1878. In 1870, the family was living in Williamsport, Pennsylvania, and Miller was working as a carpenter. He owned $4,000 of real estate and $500 of personal property. They moved to Bay City, Michigan, around 1873, and Miller worked as a millwright there. The family moved to Oscoda, Michigan, sometime in the late 1880s, but they returned to Bay City by 1900. Agnes died there of chronic Bright’s disease on December 28, 1905. Miller remained in Bay City for the rest of his life, passing away on December 16, 1919.