I don't know anything about his relatives, but the following M. Crisp listings are from Tenn.:

M. B. Crisp; pvt.; Co. F; 4 Tenn Inf. He is also listed as M. P. Crisp; pvt. Co. B; 22 Tenn. Inf. National Arvhives Box, Roll and Number 00231, 0010, 00002787. This looks like a good candidate.

M. M. Crisp Co. D; 42nd Tenn. Infan. In a sergeant out pvt. This pesons was also in the Co. K; 4th Confed. Inf. Sergeant.

M. L. Crisp; pvt.; Co. I 3(Forrest's) Tenn Cav.

The other Tenn., M. Crisp listings are repeats of the above.

I see that the Crisp family was well represented in the North Carolina Confederate forces as well.

Good luck

Wayne Adams