I'll wrap up my survey of siblings in the major leagues with a small sampling of talented brotherly duos.
The Coopers and the Ferrells are somewhat unique because they are on a short list of brothers who worked together as a pitching/catching tandem. There have been less than 20 examples of this in big league history. The Coopers worked together occasionally for the Cardinals between 1940 and 1945. The Ferrells formed a battery for the Red Sox on and off from 1934 through 1937, then again for the Senators in '37 an '38. Of the two combinations, the Coopers are the only sibling battery who worked together in a World Series and All-Star Game.
Mort and Walker Cooper
Mort was the older of the two. A right-handed pitcher, he bunched together 20-win seasons for the Cardinals every year from 1942 through 1944 and helped them to 3 straight World Series appearances. Arguably the most effective pitcher of the war years, Mort was MVP in '42, when he led the league in wins (22), ERA (1.72) and Shutouts (10). A 3-time All-Star, he got into a fiscal dispute with the St. Louis front office in '45 and ended up with the Braves. After that, the painful bone spurs he had been pitching with for several years began to rob him of his effectiveness. Two years younger, Walker played for 18 years at the major league level, hitting .285 for 6 teams. He earned 8 All-Star selections and won 2 World Series rings. He was a lifetime .300 hitter in 16 postseason games. Equipped with a strong arn, he foiled 59% of all attempted steals in '42 and 53% in 1953.
Wes and Rick Ferrell
There are some who still argue that the Committee responsible for electing a Farrell to the Hall of Fame got it backwards. The elder sibling, Rick is enshrined at Cooperstown mainly on the strength of his defense. He certainly wasn't instilling fear in the hearts of pitchers with his bat. In an 18-year career, Rick hit at a respectable but not impressive .281 clip with very little power. He was an excellent defensive catcher, however, topping the league in assists and putouts twice apiece while pacing the loop in the caught stealing category on four occasions. Rick's younger brother Wes had more jaw-dropping numbers, assembling 6 20-win campaigns in a 15-year career that stretched from 1927 through 1942. Extremely durable, he led the league in complete games four times while playing on 2 All-Star teams. He was also one of the greatest offensive pitchers of all-time, setting the record for most career homers by a hurler with 38. He was so adept with a bat that he was used as a pinch-hitter numerous times in his career. In all, he hit .280 with 107 extra-base hits.
A couple of more dynamic brotherly duos worth mentioning:
Roberto and Sandy Alomar
Born in 1966, Sandy was two years older. In a 20-year catching career, he compiled a .273 batting average for 7 big league clubs. In addition to 6 All-Star selections, he captured Rookie of the Year honors in 1990, won a Gold Glove and was MVP of the 1990 All-Star Game. He played in 2 World Series with Cleveland, hitting .311 with 2 HR and 11 RBI's in 12 games. Roberto was the more talented of the two. Though he captured a lot of negative attention when he spit in the face of umpire John Hirschbeck, the two men later became friends. Writers forgave him as well, electing him to the Hall of Fame in 2011. He got in on the strength of his 10 Gold Gloves, 12 All-Star selections, 2,724 hits and 474 stolen bases, accrued during 15 seasons. The Alomars were the sons of Sandy Sr.--who spent 15 years in the Big Show as an infielder from 1964 through '78.
Joe and Luke Sewell
A talented shortstop, Joe played 14 seasons from 1920 through 1933 and gained entry into the Hall of Fame. He was a lifetime .312 hitter who played on 2 World Series champion clubs--The 1920 Indians and 1932 Yankees. Adept with a glove, he was frequently among the league leaders in putouts, assists and double plays turned. Three years younger, Luke served as a catcher for 20 years, leading the league in assists and caught stealing 4 times apiece. When his playing days were over, he spent 10 years as a manager, guiding the Browns to their only World Series appearance in 1944.
A third Sewell brother, Tommy, warrants mentioning because he earned a cup of coffee in 1927, logging one at-bat for the Cubs. In 5 minor league seasons, he hit .280.