even in the 90s the US immigration was a bunch of wankers. when we ran a hotel in tulum in mexico we had a base in Houston, and on the US mexican border we where always waved thru without even looking at our passports. at one point I flew to germany from cancun and returned to the US a few month later. they wanted 10k bucks for overstaying because I had no exit stamp on my last visa.Luckily your not at the Mexican border.