Here are records of the 1st Texas S.S. Battalion which include distance references:

"Left Enterprise Aug 30th, arrived at Mobile, AL Aug 30th distance 120 miles. Left Mobile Aug 31st arrived Halls Mills the same day distance 12 miles."

"For Sept and Oct 1863 field and staff at Camp Cummings, Mobile Al."

"Left Halls Mills AL, Sept 18, 1863 arrived at Camp Cummings, Mobile AL same day, distance 12 miles."

Records of the 46th Tennessee, which was also stationed at Camp Cummings during the same period, show that the men did provost guard duty in the city. I don't know where the camp might have been, but it must have been on the outskirts of Mobile, just south or west of the city limits in 1863.