Northwest Airlines has operated continuously under one name longer than any other U.S. Airline.
Nearly 60 years ago, Northwest pioneered the “Great Circle Route” across the Pacific Ocean to Asia when other airlines said it couldn’t be done.
In addition to operating one of the largest domestic route networks in the U.S., Northwest carries more passengers across the Pacific Ocean (5.1 million in 2004) than any other U.S. carrier, and carries more domestic air cargo than any other American passenger airline.

Beginnings
Northwest Airlines was founded in 1 September 1926 by Col. Lewis Brittin, under the name Northwest Airways. Like other early airlines, Northwest’s focus was not in hauling passengers, but in flying mail for the U.S. Post Office Department. The fledgling airline established a mail route between Minneapolis and Chicago, using open cockpit biplanes such as the Curtiss Oriole.
Northwest began flying passengers in 1927. In 1928, the airline started its first international route with service to Winnipeg, Canada. The airline’s operations were expanded to smaller cities in the region by the end of the decade. In 1931 Northwest sponsored Charles and Anne Lindbergh on a pioneering flight to Japan, scouting what would become known as the Northwest Airlines Great Circle route, and proving that flying through Alaska could save as much as 2,000 miles (3,000 km) on a New York-Tokyo route. In 1933, Northwest was designated to fly the Northern Transcontinental Route from New York City to Seattle, Washington; it adopted the name Northwest Airlines the following year as a result of the Air Mail Scandal. Northwest stock began to be publicly traded in 1941.
Learn more about the history of the Minneapolis based airline:
http://www.nwahistory.org/
http://en.wikipedia.org/wiki/Northwest_Airlines#Beginnings