My original point stated more simply:
The 3rd Alabama Battalion was composed of 2 companies of infantry commanded by Maj. John S. Garvin. Capt. Elbert C. Leach was a company commander in the 3rd Alabama Battalion and not a cavalry commander as some online Fort Henry order of battle's indicate (for example: http://aotn.homestead.com/fthenryoob.html ).
The Alabama Battalion of Cavalry was not an official unit but was composed of 2 independent cavalry companies commanded by Capt. William Houston and Capt. David C. Hubbard. Houston's Company was mustered into service at Cherokee, Franklin County, AL on 21 Dec 1861. Hubbard's Company was mustered into service at Landersville, Lawrence County, AL on 17 Dec 1861. Both companies were transported from Florence, AL to Fort Henry by riverboats after 19 Jan 1862.