In Texas, which from what I understand from the O.R. had the largest active operational collection of United States troops in any state, due to the border which Mexico and Indian raids. A total of over 2,600 troops, three regiments of infantry and one of cavalry with a few artillery companies. The following list of Federal installations were abandoned by those forces.
The military Department of New Mexico was also abandoned.
Due to the amount of time for some of these units it took to leave the state a number were taken prisoners after Fort Sumter was fired upon. These were release by President Davis who recognized the earlier agreements.
Charlston was nothing compared to size of the turnover and military importance of these post.