In 2001, Trans World Airlines (TWA) was acquired by American Airlines and the list of major legacy US airlines grew ever-shorter (now only four remain). Founded in 1930, TWA was one of the most recognizable early US airlines and one of the most famous carriers of the jet age. While its legacy (including that of the Boeing 747) may not be as great as Pan Am, it was considered the nation’s second unofficial flag carrier. Here is a look at TWA’s historic fleet of Boeing 747s.