Emmanuel Cave was born around 1838 in Ohio to Nathaniel and Elizabeth Cave. His father was a laborer. He probably grew up in Pickaway County, Ohio, and he married Susan Bender there on May 23, 1861. They had at least seven children: William, born around 1869; Florence, born around 1872; Harry, born around 1873; Rosa, born around 1876; Bunn, born around 1878; Roy, born around 1879; and Bertha, born around 1882. He enlisted in the Union army on February 6, 1862, and mustered in as a private in Company H of the 69th Ohio Infantry on March 8.
The regiment took part in the Battle of Stones River, the Battle of Chickamauga, the siege of Chattanooga, the Battle of Missionary Ridge, the Atlanta campaign, the March to the Sea, and the Carolinas campaign. He mustered out in Louisville, Kentucky, on July 17, 1865. Cave returned to Circleville, Ohio, after the war and earned a living as a farm laborer. By 1870, he owned $700 of real estate. By 1880, he was working as a well digger. He applied for a federal pension in May 1882 and eventually secured one. He remained in Circleville for the rest of his life, and he died there on May 15, 1916.