Denny grew up in the Doylestown area youth leagues and semi-pro leagues before launching an 18-year professional baseball career. He started his major league career with the Cleveland Indians and later played for the Boston Red Sox and St. Louis Browns. Galehouse pitched the 1948 American League Playoff game for the Red Sox, losing to the Indians' Gene Beardon, 8-3. In the 1944 World Series between the Browns and St. Louis Cardinals, Denny won two games while compiling a 1.50 ERA. He has remained active on the area sandlots as a major league scout seeking new talent for the big leagues.