I recently talked to an old man in a southern town who said when he was very young, there was a "Confederate barracks" across the street from him. What did this refer to?

If you can give me more specific information about the location I might be able to shed some light on your question. In the Southern United States these sorts of places were actually very common. Organizations such as the United Confederate Veterans were very popular throughout the late 19th early and 20th century. You can access the records of the UCV online here: http://www.lib.lsu.edu/sites/default/files/sc/findaid/1357.pdf