IAH international -> domestic

Hi everyone, I have a trip booked for next month in which I will by flying Sydney to Houston and then a layover before going on to Denver. I am very excited for the trip but one thing that has me nervous is the layover in Houston is at 1 hour and 30 minutes. It is all on the same ticket through United. Does anyone who is familiar with the Houston airport have any thoughts on the matter? Is it enough? I will have both carry on and checked luggage with me. As I understand I will have to collect and recheck my luggage after passing through customs which may add to the time. I am not a frequent flyer but I’m assuming if it is all booked on the same ticket the airline is compelled to help you get there?

Would greatly appreciate any insight!

Edit: it is on a Monday if that changes anything