Hilton is celebrating its 100th birthday this year, but today is the actual birth date: On May 31, 1919, Conrad Hilton opened his first hotel in Cisco, Texas, the existing Mobley Inn when he was 32. It wasn't, however, until 1925 that he built the first hotel to carry the Hilton name: the Dallas Hilton. Since then, Hilton has grown to operate more than 5,500 properties in 109 countries and territories under 16 different brand names, with more than 60 million Hilton Honors members.