The Aberdeen "Pippins" became charter members of the four–team Class D level Southwest Washington League.
[1] The Centralia Midgets, Hoquiam Perfect Gentlemen and Olympia Senators joined Aberdeen as charter members in beginning league play on May 10, 1903.
[4] In their first season of play, the Aberdeen Pippins won a Southwest Washington League championship amidst controversy.
The league continued the practice of only counting weekend games in the standings, while playing six times per week overall.
Ending the season with a record of 10–8, Aberdeen played under managers Bill Campbell and Bob Brown.
The Pippins finished 4.0 games behind the 1st place Hoquiam Perfect Gentlemen (14–4) in the final standings.
[16] On May 22, 1903, the ballpark hosted President Theodore Roosevelt, who was in attendance for the Aberdeen home game against Olympia.