Texans in border communities used to cross back and forth freely with little to no documentation . Much has changed since the terrorist attacks on Sept. 11, 2001. The 9/11 Commission in 2004 determined the border crossing rules were too lax, and Congress passed the Western Hemisphere Travel Initiative , which required U.S. border crossers to possess passports or passport cards to cross the international ports of entry. Mexican travelers are required to carry a Border Crossing Card . The