On 16 April 1961, six Super Sabres were deployed from Clark Air Base in the Philippines to Don Muang Royal Thai Air Force Base in Thailand for air defense purposes; the first F-100s to enter combat in Southeast Asia.[18] From that date until their redeployment in 1971, the F-100s were the longest-serving U.S. jet fighter-bomber to fight in the Vietnam War. Serving as MiG combat air patrol escorts for F-105 Thunderchiefs, Misty FACs, and Wild Weasels over North Vietnam, and then relegated to close air support and ground attacks within South Vietnam.
Source: Wikipedia