Newark opened in 1928 on reclaimed marshland along the Passaic River and quickly became the principal airport for New York City, claiming the first paved commercial-airport runway in the United States. By the early 1930s it was the busiest airport in the world, a hub for the pioneering airmail system and early airline networks. Its dominance ended when LaGuardia opened in 1939. The Port Authority of New York and New Jersey took over the field in 1948, beginning decades of methodical rebuilding.
The modern three-terminal layout took shape in the 1970s, and Newark's fortunes rose again when People Express and later Continental Airlines built a major hub there in the 1980s. Continental's 2010 merger folded that operation into United Airlines, which now operates Newark as its primary transatlantic gateway.
The airport was renamed Newark Liberty after the September 11, 2001 attacks; United Flight 93 had departed from Newark that morning. A gleaming new Terminal A opened in 2023, replacing one of the most dated major terminals in the country, with Terminal B next in line for eventual replacement and signaling a broader modernization of the airport.