Are these African American's you speak of, listed at the State of Texas troops, or listed as Confederate?
The Confederate Government didn't recognize Blacks to be "Soldiers" as per a letter written Confederate Sec. of War, James A. Seddon...
[NOVEMBER] 24, 1863.
Our position with the North and before the world will not allow the employment as armed soldiers of negroes. If these creoles can be naturally and properly discriminated from negroes, the authority may be considered as conferred; otherwise not, unless you can enlist them as navvies (to use the English term) or for subordinate working purposes.
J. A. S., Secretary.
http://ebooks.library.cornell.edu/cgi/t/text/pageviewer-idx?c=moawar&cc=moawar&idno=waro0128&node=waro0128%3A3&view=image&seq=953
We know through impressment acts that Blacks/Slaves served in all kinds of capacities, but I know of no "Soldiers" as such. Plenty of Slaves faithfully followed their masters into the ranks, but "Soldiers" they were not, in my thinking.
Author Dr. Bruce Levine's book Confederate Emancipation is a great read on the subject...
http://www.amazon.com/Confederate-Emancipation-Southern-Slaves-during/dp/0195315863/ref=sr_1_1?ie=UTF8&qid=1344379149&sr=8-1&keywords=Confederate+emancipation
He has a great lecture on youtube on the subject...
http://www.youtube.com/watch?v=VjBwCSZC-20&playnext=1&list=PLBF2579554AE6E8D4&feature=results_main
I do not know of any Blacks/Slaves being willfully armed by the Confederate Government. I have no proof that those few who joined Black Regiments sanctioned by the Confederate Government right at the close of the war, were even armed.
Blog site http://deadconfederates.com/on-black-confederates/ has some compelling research on the subject that makes interesting reading.
Kevin Dally