He attended the public schools and Poplar Springs College, Kentucky. He studied law and was admitted to the bar and commenced practice in Livingston, Tennessee. He also engaged in agricultural pursuits.
1st Tennessee Mounted Infantry Regiment, U.S.A.: Recruiting for this regiment was begun October 1863, and two companies had been mustered into service by the end of 1863; other companies were added during 1864, the last one on November 30, 1864. Abraham E. Garrett was promoted from major to lieutenant colonel on March 18, 1864. The companies were organized at Nashville and at Carthage, and did duty in the District of Middle Tennessee, Department of the Cumberland, until April 1865, when the regiment was assigned to the 1st Brigade, 1st Subdistrict, District of Middle Tennessee.