With the start of the ACC Tournament era in 1973, Wilhelm began a stretch of 11 regular season conference championships in 13 seasons (through 1985), including seven consecutive from 1973–1979. In the next 13 season (1960–1972), however, Clemson made only one NCAA Tournament appearance, in 1967. In his first two seasons, Wilhelm led the program to two Atlantic Coast Conference (ACC) championships and its first two College World Series appearances, in 19. In September 1957, Wilhelm accepted the head coaching position at Clemson. Prior to his final season of professional baseball in summer 1957, Wilhelm had served as an assistant baseball coach for the North Carolina Tar Heels in spring 1957. He appeared in a total of 401 minor league games, hitting. He played his final season of professional baseball in summer 1957, with the Greensboro Patriots of the Boston Red Sox organization. Wilhelm played the 19 seasons in the Milwaukee Braves system, advancing as high as the Double-A Atlanta Crackers. After the 1954 season, which he split between the Columbus Cardinals and the Allentown Cardinals, Wilhelm left the Cardinals organization. In 96 games with the Paducah Chiefs of the Class D Kentucky–Illinois–Tennessee League, he batted. In 1953, Wilhelm returned from military service and had his most successful minor league season.

Wilhelm then spent two years out of baseball from 1951 to 1952, when he served in the United States Army in the Korean War. Louis Cardinals organization in 1950, splitting that season between the Goldsboro Cardinals and the Allentown Cardinals. Wilhelm played two seasons of college baseball at NC State, and he signed a professional contract with the St.

Before coming to Clemson, Wilhelm played several seasons of minor league baseball and served one season as an assistant baseball coach at North Carolina.

In his 36 seasons as head coach, Wilhelm had a record of 1,161–536–10.

Bill willingham