I have to believe the average American movie-goer these wouldn't know what the Alamo was unless Britney Spears gave a concert there. They probably thought the movie was about a breed of dog from Alaska. ;)
Well, you'd be wrong then. The Alamo is where Pee Wee Herman's bike was hidden in the basement. I think that there are a lot of people who know that and not all of them are Britney Spears fans.