Walter Cleveland Stewart, known simply as "Lefty," was a durable left-handed mainstay who provided the St. Louis Browns with high-level stability during a period of league-wide offensive volatility. While he spent six seasons in the Browns' rotation (1927–1932), it was his final three years in St. Louis that cemented his legacy as one of the franchise's premier arms of the Depression Era.

Stewart’s 1930 campaign remains one of the most underrated individual seasons in Browns history. In a year where the league-wide ERA was sky-high, Stewart defied the trend by winning 20 games and posting a 3.45 ERA, which ranked third-best in the American League. His value was confirmed by advanced metrics, as he finished third in the AL in Pitching bWAR (7.2), trailing only Hall of Famers Lefty Grove and Wes Ferrell. Stewart was a workhorse who specialized in the complete game, providing the Browns with a competitive edge every fifth day.

His tenure in St. Louis came to an end in 1932, when he was traded to the Washington Senators, where he would immediately help his new club reach the World Series. He left the Browns with 73 wins and a reputation as a pitcher who thrived in an era dominated by hitters.