Had a tight int’l to domestic connection DFW about a month ago. 1.5 should be fine if you have just a carry on. If you don’t have GE, use the mobile passport app to get through passport control quicker. And when you exit baggage claim, i recommend the security line to the left (toward D18) as you exit…usually shorter in my experience. the security lines right near the intl exit always had a long line, especially with the bank of international arrivals in the afternoon..