Campau's success as a baseball player is largely attributed to two talents: power and speed. He is probably most referenced in baseball's record books for having won the American Association's home run championship in 1890. Although minor records from the 1880s and 1890s are incomplete, he hit at least 135 home runs in his professional baseball career, including a high of 20 home runs in 1894. This he accomplished during a deadball era before the home run became a major offensive weapon in baseball. His power was surprising, too, given his slight build at 5 feet, 11 inches, and 160 pounds. In its obituary of Campau, the 1939 Spalding Guide wrote that, despite his slight build, Campau "seemed to get extraordinary power from his wrists and arms".