Northwest Airlines (often abbreviated as NWA) was a trunk carrier and a major airline in the United States that operated from 1926 until it merged with Delta Air Lines in 2010. The merger made Delta the largest airline in the world until the American Airlines–US Airways merger in 2013.
Northwest was headquartered in Eagan, Minnesota, near Minneapolis–Saint Paul International Airport. After World War II, it became dominant in the trans-Pacific market with a hub in Tokyo, Japan (initially Haneda Airport, later Narita International Airport). In response to United Airlines' 1985 acquisition of Pan Am's Pacific routes, Northwest paid $884 million to purchase Republic Airlines and then established fortress hubs at Detroit Metropolitan Wayne County Airport and Memphis International Airport. With this merger, NWA established the domestic network necessary to feed its well-established Pacific routes. Lacking a significant presence in Europe, in 1993 it began a strategic alliance with KLM and a jointly coordinated European hub at Amsterdam Airport Schiphol.