Forgotten today, Sam Thompson (1860-1922) was one of the most dominant five skills players of his era. At the plate, he batted .331, was second among 19th century players in home runs, and ranks first all-time in RBI per game (.923). In his prime, he averaged 25 steals a season. Defensively, he registered 283 outfield assists (12th all-time), and is first among all outfielders (with 1,000 games) in his ratio of assists per game with one every 4.9 games. Using a primitive fielding glove with no webbing or pocket, he compiled the highest fielding average of any outfielder (1,000 games) who completed his career before 1900. At age 46, 10 years after his last full major league season, Thompson played eight games for the injury-plagued Detroit Tigers, winning one contest with his bat and saving several others with spectacular catches in the outfield. This comprehensive biography traces Thompson's life and career from his childhood in rural Danville, Indiana, to his last days as a U.S. deputy marshall in Detroit, and clarifies his status of one of the greatest players in baseball's long and storied history.