The Orphan Brigade was the nickname of the First Kentucky Brigade, a group of military units from Kentucky who fought for the Confederacy during the War Between the States.
 Major General John C. Breckinridge, former Vice President of the United States, was the brigade’s original commander. When Breckinridge was promoted to division command he was succeeded by Brig. Gen. Roger W. Hanson, who fell at the Battle of Stones River.Tennessee on January 2, 1863.
The name came when the brigade suffered heavy casualties during the battle. In the aftermath Confederate General Braxton Bragg supposedly rode among the survivors crying out repeatedly “My poor Orphans! My poor Orphans”. This information was according to Brigade historian Porter Thompson in his 1868 history of the Unit. 
The name probably came because the State of Kentucky stayed neutral during the war, so these men who fought for the Confederacy were viewed as orphans. Interestingly, Kentucky was represented by a star in the flags of both the United States and the Confederate States of America.
The Orphan Brigade lost another fine commander at the Battle of Chickamauga, Tenn. on Sept. 20, 1863 when Brig. Gen.  Benjamin Hardin Helm was mortally wounded when he was shot in the chest by a sharpshooter from the 15th Kentucky Union infantry. Helm was the brother-in law of Mary Todd Lincoln, wife of Union President, Abraham Lincoln.
Edwin Porter Thompson who wrote the “History of the First Kentucky Brigade” and the “History of the Orphan Brigade”  tells that the Brigade served throughout the Atlanta Campaign of 1864 and then opposed Union Commander General William T. Sherman’s infamous “March to the Sea”. The Orphan Brigade ended the war fighting in South Carolina in late April 1865 and surrendered at Washington, Georgia on May 6-7, 1865.