John Henry Eaton Jr. was born on December 5, 1829, in Sutton, New Hampshire, to John Henry and Janet (Andrew) Eaton. Eaton graduated from Dartmouth College in 1854, after which he served as the Superintendent of Schools in Toledo, Ohio. He later studied theology in Andover, Massachusetts, and was ordained a Minister of the Gospel by the Presbytery of Maumee in 1861. When the Civil War broke out, Eaton enlisted in the 27th Ohio Infantry as a chaplain. In November 1862, General Ulysses Grant put Eaton in charge of the contraband camps, which cared for and organized the numerous formerly enslaved people whom had escaped to freedom behind Union lines. Eaton's excellent service in this position earned him a commission as a Colonel (and later Brigadier-General) in the 63rd U. S. Colored Infantry. Eaton married Alice Eugenia Shirley (1844-1927) on September 29, 1864, and resigned his military commission three months later. In May 1865, Eaton moved to Washington, D.C., to take a position as the assistant commissioner of the newly formed Freedmen's Bureau. He soon left this position in order to publish the Memphis Post (1866-1867), a decidedly pro-Union newspaper. He was elected Superintendent of Schools in Tennessee in 1867 and became the U. S. Commissioner of Education in 1870. After his resignation (due to poor health) in 1886, Eaton served as President of Ohio's Marietta College (1885-1891) and of Utah's Sheldon Jackson College (1895-1899). He began work on Puerto Rico's public school system during the American military occupation of 1899, but resigned in 1900 due to poor health. He died in Washington, D.C., on February 9, 1906, and is buried in Arlington National Cemetery.