The 4,000-man 1st Kentucky Brigade was organized in the summer of 1861.  In February 1862, the Confederate army was forced out of Kentucky, and with it went the 1st Kentucky Brigade, never to return during the war. This forced exile gave the unit its nickname, "Orphan Brigade."

The Orphan Brigade covered itself with glory in the battles it fought with the Confederacy's Army of Tennessee: the battles of Shiloh, Corinth, Vicksburg, Baton Rouge, Stones River, Jackson, Chickamauga, and Missionary Ridge, as well as throughout the Atlanta campaign and against Sherman during his march to the sea. Gen. Joseph E. Johnston and Gen. John B. Hood, who served at different times as commander of the Army of Tennessee, both declared the Orphan Brigade the best in their army. President Abraham Lincoln's brother-in-law, Ben Hardin Helm, was one of the Orphan Brigade's generals until he was killed at Chickamauga. Another of its generals, Roger W. Hanson, was killed in the tragic Confederate charge during the final day of battle at Stones River. Of the 1,200 members of the Orphan Brigade engaged in the charge, 400 did not return. Division commander and former U.S. vice president John C. Breckinridge rode among the survivors crying, "My poor orphans! My poor orphans!"

One of the last Confederate units in the East to surrender, the soldiers of the Orphan Brigade laid down their arms in the first week of May 1865, at Washington, GA. Only 500 of the original 4,000 members of the brigade remained.