Sounds like your husband is an ironworker. What he does is one tough job and it take a lot of skill. No illegals are going to waltz across the border and do his job. My brother-in-law is a tile setter and I've worked with him a couple of times. Thats a tough job, too but he does work indoors mostly.
Actually, he's a crane operator. He drills the holes down in the ground to support the columns on large bridges and then he runs the crane that lifts the beams up to the ironworkers. He has a lot of respect for iron workers and they have a lot of respect for him. They're never afraid to ride the mancage if he's the one operating the crane because they trust him and know him to be a safe operator. Yep, it's a highly skilled occupation and so far illegals haven't been able to horn in on it.
I'm not familiar with the employment picture in the St. Louis area. Are there a lot of illegals over there yet? Here in rural Southwest Missouri there aren't yet, unless they're hiding out on some of the big farms and ranches around here.