He was named the National League (NL)'s Most Valuable Player (MVP) twice, and was a member of one World Series championship team.

"[2] He took a job with the Swift and Company meat industry plant as a messenger boy when he was 10, and he also served as a substitute infielder on its baseball team.

[4] He also played baseball for North Side High School until 10th grade, when he dropped out to take a full-time job at Swift.

[7][8] The Denison team changed its name to the Railroaders and joined the Western Association in 1915, and raised Hornsby's salary to $90 per month ($2,711 today).

[9] At the end of the season a writer from The Sporting News said that Hornsby was one of about a dozen Western Association players to show any major league potential.

[9] Hornsby came to the attention of the Major League St. Louis Cardinals during an exhibition series between that team and the Railroaders in spring training in 1915.

[13] The Cardinals picked up Roy Corhan from the San Francisco Seals of the Pacific Coast League to play at shortstop in 1916, making Hornsby one of three candidates for the position.

[17] After playing nearly every game throughout the first month of the season, Hornsby was called away from the team on May 29 after his brother William was shot and killed in a saloon.

[23] He was still among the league leaders in triples and slugging percentage in 1918, but after the season ended with the Cardinals in last place, he announced that he would never play under Hendricks again.

[27] On June 4, he had two triples and two RBIs as the Cardinals defeated the Chicago Cubs 5–1, a game that ended future Hall of Famer Grover Cleveland Alexander's 11-game winning streak.

After negotiating with Cardinals management he settled for three years at $18,500 ($336,751 today), which made him the highest-paid player in league history to that point.

[32][33][a] On August 5, Hornsby set a new NL record when he hit his 28th home run of the season, off Jimmy Ring of the Philadelphia Phillies.

[36] Hornsby set National League records in 1922 with 42 home runs, 250 hits and a .722 slugging percentage (still the highest ever for players with 600+ at-bats).

[37] He returned 10 days later, but the injury lingered, and he was removed from a game against the Pirates on May 26 to be examined by Robert Hyland, the Cardinals' physician.

The final out of game seven came when Hornsby tagged out Babe Ruth on a stolen base attempt, giving the Cardinals their first World Series title.

When Hornsby refused to give way, the Cardinals traded him to the New York Giants for Frankie Frisch and Jimmy Ring on December 20, 1926.

[50][51] The trade was briefly postponed as NL president John Heydler stated that Hornsby could not play for the Giants while he held stock in the Cardinals.

He was a player-coach, and served as acting manager for part of the year after John McGraw briefly stood down due to sinusitis.

Additionally, his gambling problems at the race track and distrust of Giants' management annoyed team owner Charles Stoneham.

Over the next year-and-a-half, Veeck grew increasingly dissatisfied with Hornsby, believing his autocratic managing style hurt team morale.

By this time, the Cardinals were in fifth place and long out of the pennant race, and Breadon was concerned that Hornsby was no longer able to play regularly.

The Browns finished in last place in the AL. That year, Hornsby began operating a baseball school in Hot Springs, Arkansas, which he ran on and off between 1933 and 1951 with various associates.

[13] The regression came in part because Ball's estate, which was running the Browns pending a sale, refused to infuse badly-needed capital into the team.

[75] In the winter of 1936, the Ball estate sold the Browns to Donald Lee Barnes, who retained Hornsby as manager on Rickey's advice.

On April 21, in his first game of the year, Hornsby hit the final home run of his career in a 15–10 victory over the Chicago White Sox.

[84] He signed as a player-coach with the Baltimore Orioles of the International League in 1938 before leaving them to play for and manage the Chattanooga Lookouts of the Southern Association for the rest of the season.

[88] Hornsby won two games inserting himself as a pinch hitter in the ninth inning, including one occasion in which he drove in three runs with a bases-loaded double.

[97] He won seven batting titles in total, number three all-time at the time of his retirement, and a feat tied or exceeded by only five players (Cobb [11 or 12, depending on the source], Tony Gwynn [8], Honus Wagner [8], Rod Carew [7], and Stan Musial [7]).

[110] His compulsive gambling was often a factor in his dismissal from a team; by one account, he lost at least one managerial job for placing a bet during a game.

[116] In 2001, writer Bill James ranked him as the 22nd-greatest player and the third-greatest second baseman in baseball history, while at the same time documenting his unpopularity and his difficult personality.