David McKendree Key was born in 1824 near Greenville, Tennessee. He studied law while attending Hiwassee College and became that institution’s first graduate in 1850, the same year he was admitted to the Tennessee state bar. He then practiced law in Tennessee.

With the outbreak of the Civil War, Key became adjutant general of the First Tennessee Corps before being promoted to lieutenant colonel of the Forty-third Regiment of the Tennessee infantry. He saw action in several battles, was captured and then released, and at war’s end returned home to Tennessee, where he took up farming. Following the war, Key was chosen as a member of the state constitutional convention in 1870, and later that year, became chancellor of the Third Chancery Division. He remained in that post until 1875, when he was tapped to fill a vacancy in the U.S. Senate.

Key, a Democrat, served in Congress until 1877, when he was defeated in his bid for reelection. That same year, President Rutherford B. Hayes nominated Key as his postmaster general, a position Key held from 1877 until 1880. During his tenure, Key encountered opposition from Democrats, who viewed him as a traitor for serving in a Republican presidential administration, and from Republicans, who saw him as a traitor for having fought for the Confederacy during the Civil War. Soon after he left office, Key was criticized for allegedly allowing the “Star Route” frauds to continue unchecked.

From 1880 until 1894, Key served on the U.S. District Court for the Eastern and Middle Districts of Tennessee, having been appointed to the job by President Hayes. David McKendree Key died in 1900.