Jackie Robinson played 10 seasons in Major League Baseball, from 1947 through 1956. Every one of those MLB seasons was with the Brooklyn Dodgers.
Robinson made his major-league debut on April 15, 1947, becoming the first Black player in the modern major leagues. He won the inaugural Rookie of the Year award that season and became the National League's Most Valuable Player in 1949. His career ended after the 1956 season, when he was 37 years old.
The figure ten counts MLB seasons, not all of Robinson's professional baseball years. Before reaching Brooklyn, he played for the Kansas City Monarchs of the Negro leagues in 1945 and for the Dodgers' minor-league affiliate, the Montreal Royals, in 1946. During his decade in the majors, Robinson reached six World Series and helped Brooklyn win the 1955 championship—the franchise's first title since moving to Los Angeles.