The Alabama Department of Transportation currently operates eight welcome centers for visitors entering the state from Tennessee, Georgia, Florida and Mississippi. Only one is not located on an Interstate highway.
The Houston Welcome Center is on US 231 just across the Florida line near the small town of Madrid south of Dothan. We have passed it many times on our way back from trips to Apalachicola and St. George Island or our daughter Becca's house near St. Augustine. We've stopped a few times as well, and I took photos on our last trip.
In 2018 Kelly Kazek published an article on various marble welcome signs around the state, including this one. A few more comments are below.
This sign is now itself an historical monument. Was the last upgrade to this welcome center made during Guy Hunt's administration?