Purple Martins are a southern tradition. They come north from Mexico each year and come to Louisiana (and many other states) in the spring. My father and grandfather always had Martin houses, believing that they ate their weight in mosquitoes every day. There's some question about that, but the fact remains that Martins are graceful fliers, they sing a beautiful song, and they're fun to watch.
Daddy always had a Martin house, but he didn't have much luck with the last one he erected. He thought that the Martins didn't like it, but I always thought that it was sited wrong, and it wasn't the house, it was the siting. When Dad died, the Martin house stayed where he put it, till last year, when Mom moved and gave me the Martin house. I set it up in a corner of the yard, and while te birds inspected it, they never really moved in. They're seasonal migrants, and had already made their nests when I put the house in the corner of the yard. Still, I figured they'd remember where I put it, and sure enough, this afternoon I heard the song of a Purple Martin.