The Team Drivers International Union was formed in 1901, but some of the 1,700 members soon broke off to form Teamsters National Union, a rival organization. With guidance from American Federation of Labor leader Samuel Gompers, the two unions rejoined in 1903 to create the International Brotherhood of Teamsters.
The first teaming local in Seattle formed in 1899. Organized by Billy Middleton, it disbanded in 1907 owing to weak activity. The men who drove wagons still felt that they'd be stronger in solidarity and reorganized.
When Teamsters Local 174 was chartered on February 19, 1909, total membership was 400 and grew quickly due to the changing nature of transportation. The auto age had begun, and motor truck drivers were brought into the fold.