 All eight teams are affiliated with a major league team.The Northwest League (or the "Northwestern League") has existed in various forms since 1890, and has been in its current incarnation since 1955.The current NWL is the descendant of the Western International League (WIL), a Class B league from 1937 to 1951 (with a stoppage during World War II) and Class A from 1952 to 1954.