Originally Posted by
mlamarca
I have made one hour connections through IAH, having to clear immigration/customs, without a problem. You don't specify which day of the week, and as someone else stated, weekends take a bit longer than immigration on a Wednesday.
An hour's connect time is nowhere near enough time on an international flight, especially if you're in coach since it will take longer to get off the plane and thus won't be one of the first in line at customs. If the flight is even a little bit late you definitely won't make it even without customs. Don't chance it.