Smallwood, a graduate of Samford University, served as a judge for 44 years, retiring in 2006. Smallwood served in the U.S. Army Reserves in the Judge Advocate General Corp attaining the rank of Colonel. He served twice as president of the Alabama Judges Association, and was also a minister and served in numerous churches, and was a member of South Roebuck Baptist Church. Smallwood was an author of three books and was working on a fourth book at the time of his death.
Smallwood and his wife of 56 years, Shirley Callaway Smallwood, had a daughter, Sunny; 3 sons, Alan, J. T., and David; and one granddaughter. Smallwood is interred at Jefferson Memorial Gardens in Trussville.
- Smallwood, Tennant M. (2005) Is The Bible Really The Law?
- Smallwood, Tennant M. (2011) The Bull Falls Twice: The Life of Eugene "Bull" Connor. Altona, Manitoba: Friesans Book Manufacturing
- Smallwood, Tennant M. (2011) Gamblin', Gamblin', Politics & Old Time Fueds.
- Velasco, Eric (May 12, 2011) "Memorial to honor Judge Smallwood planned for today." Birmingham News