The colonel's name was W. M. Voorhies.

When two regiments exist from the same state and have the same numeric designation, convention usually dictates that the colonel's name be used to distinguish one from the other. In this case, the name 'Voorhies' helps us tell Voorhies' 48th Tennessee Regiment from Nixon's 48th Tennessee Regiment.

Five men named Coffee served in the company you listed. Isaac Coffee might have served in Biffle's 19th Tennessee Cavalry later in the war.

Here's a unit history --
http://www.tngennet.org/civilwar/csainf/csa48v.html

You can order military service files here --