April 16 - In Los Angeles‚ Steve Souchock of Sacramento (PCL) belt home runs in the 7th‚ 8th and 9th innings in a 19–6 win. The last homer is a grand slam as Souchock drives in nine runs. The veteran will hit 30 homers this year and be back in the majors in 1951 with the Detroit Tigers.
President Harry Truman throws out two balls at the Washington Senators' opener - one left-handed and the other right-handed - and then watches the Senators beat the Philadelphia A's 8-7. When rain starts falling in the 6th inning, he puts on a raincoat and remains to the end.
At the Polo Grounds‚ Sam Jethroe becomes the first black to play for the Boston Braves. In his major leaguedebut. Jethroe goes 2-for-4‚ including a home run to lead the Braves to an 11–4 beating of the New York Giants. Warren Spahn is the winning pitcher. Jethroe will go on to become National League Rookie of the Year.
St. Louis Cardinals third baseman Tommy Glaviano makes three errors on successive plays in the 9th inning that lets in four runs in a 9–8 loss. The Brooklyn Dodgers trail by an 8–0 score in the game, and close to 8–5 in the 9th while have the bases loaded, when Glaviano experiences his nightmare. Glaviano ties a major league record set most recently by Dodgers Billy Cox last year.
July 2 - Cleveland Indians great Bob Feller wins his 200th major league game, 5–3, over the Detroit Tigers in the second game of a doubleheader split. Detroit wins the opener 8-5 for their only win in the 4-game series.
July 11 - Making a leaping, off-the-wall catch of a Ralph Kiner drive in the first inning, Ted Williams fractures his left elbow in the All-Star Game at Chicago's Comiskey Park. Remaining in the game, Williams puts the American League ahead, 3–2, with an RBI single. Kiner's 9th-inning homer ties the game, and Red Schoendienst's blast in the 14th inning wins it for the National League, 4–3. Williams will later state he was never the same after this injury.
August 31 - Gil Hodges of the Brooklyn Dodgers becomes the sixth Major Leaguer to belt four home runs in a single game. Hodges hits home runs off of four different Boston Braves pitchers and finishes the game with nine runs batted in. Brooklyn trounces Boston, 19–3.
September 30 - The Brooklyn Dodgers pulls within one game of the National League lead, winning 7–3 over the Philadelphia Phillies in the first of a two-games series at Ebbets Field. Duke Snider and Roy Campanella hit home runs for the Dodgers, as Erv Palica (13-8) is the winning pitcher. Bob Miller (11-6) is the loser. It is the Phillies fifth loss in a row, their eighth in 10 games, while the Dodgers have now won 13 of their last 16 games. For the second year in a row, the NL pennant race will come down to the last game. If the Dodgers win tomorrow, the race will end in a tie with the Phillies' Whiz Kids.
October 7 - The New York Yankees defeat the Philadelphia Phillies, 5–2, in Game 4 of the World Series to win undefeated their thirteenth World Championship. The Phillies will not appear again in the postseason until 1976, and they will not appear again in the World Series until they won it for the very first time in 1980.
November 26 - The Gillette Safety Razor Co. signs a six-year deal, worth an estimated $6 million, with Major League Baseball for the television and radio rights for the World Series.
November 27 - The Boston Red Sox sign veteran shortstop Lou Boudreau to a two-year contract worth an estimated $150,000. Boudreau, a player-manager for the Cleveland Indians, had asked Cleveland to give him his unconditional release after 13 years with the club.
January 26 - Chick Autry, 46, backup catcher for the Yankees, Indians and White Sox in the 1920s
January 29 - Monroe Sweeney, 57, National League umpire from 1924 to 1926.
February 11 - Kiki Cuyler, 51, outfielder for four NL teams, primarily the Cubs, who batted .321 in his career while leading the NL in runs twice and steals four times; hit a 2-run, 2-out double off Walter Johnson in the eighth inning of Game 7 of the 1925 World Series for a 9-7 lead, clinching the title for the Pirates
March 25 - Pussy Tebeau, 80, a 19th-century outfielder who played for the Cleveland Spiders
April 11 - Dick McCabe, 54, pitched from 1918 to 1922 for the Boston Red Sox and Chicago White Sox
April 23 - Bill Hallman, 74, played four seasons including two seasons for the Pittsburgh Pirates from 1906 to 1907.
May 4 - Vince Molyneaux, 61, pitcher for the St. Louis Browns (1917) and Boston Red Sox (1918)
June 8 - Cannonball Titcomb, 83, pitcher for four different clubs from 1886–90, who threw a no-hitter in the 1890 season
July 23 - Bill Lange, 79, top Chicago Colts hitter during the 1890s. Played seven seasons before retiring to get married.
September 23 - Sam Barry, 57, coach at USC since 1930 and one of the principal forces behind the creation of the College World Series, which his team won in 1948
September 25 - Pep Deininger, 72, German pitcher/center fielder for the Boston Americans and Philadelphia Phillies between 1902 and 1908
November 4 - Grover Cleveland Alexander, 63, Hall of Fame pitcher who won 373 games with the Phillies, Cubs and Cardinals and earned the pitching Triple Crown three times (1915, 1916, 1920)
November 16 - Frank Hemphill, 72, outfielder for the Chicago White Sox and Washington Senators in the 1900
December 5 - Bill Dahlen, 80, shortstop who owned the record for career assists at the position (7,500) and ended his career having played more games than anyone in major league history (2,443)