Northwest Airlines was founded on September 1, 1926, by Colonel Lewis Brittin, under the name Northwest Airways, a reference to the historical name for the Midwestern United States that derived from the Northwest Territory. Like other early airlines, Northwest's focus was not in hauling passengers, but in flying mail for the U.S. Post Office Department. The airline was originally based in Detroit, Michigan. The fledgling airline established a mail route between Minneapolis and Chicago, using open-cockpit biplanes such as the Curtiss Oriole and the Waco JYM. From 1928 the enclosed cabin six-passenger Hamilton H-45 and H-47 designs were used.
Northwest Airlines Douglas DC-3 Northwest Airlines began carrying passengers in 1927. In 1928, Northwest started its first international route with service to Winnipeg. The airline's operations had expanded to many smaller cities in that region by the end of the 1920s. In 1929, a group headed by Richard Lilly, a businessperson from St. Paul, Minnesota, purchased the airline.
In 1933, Northwest airlines was selected to fly the "Northern Transcontinental Route" from New York City to Seattle, Washington. It adopted the name of Northwest Airlines during the following year as a result of the Air Mail scandal. Northwest Airways, Inc. changed its name to Northwest Airlines, Inc. and the airline was incorporated under its new name in the State of Minnesota.
By 1939 Northwest had five daily flights from Chicago to Minneapolis; three continued west to Seattle through North Dakota and Montana. Northwest also served Winnipeg, Manitoba and Portland, Oregon by spurs from its transcontinental route.
Northwest Airlines common stock began to be publicly traded in 1941.