When will U.S. Citizens be required to carry a passport or other acceptable document for WHTI?

Since January 23, 2007, all citizens of the United States, Canada, Mexico, and Bermuda have been required to present a valid passport when entering the United States at any airport. Due to longer than expected processing times for passport applications in the face of record-breaking demand, the federal government is making an accommodation for air travel. U.S. Citizens traveling to Canada, Mexico, the Caribbean and Bermuda who have applied for but not yet received passports can nevertheless temporarily enter and depart from the United States by air with a government issued photo identification and Department of State official proof of application for a passport through Sept. 30, 2007.  more