The following are the events that happened world-wide throughout the sport of baseball.
- 1883 - National League baseball returned to the City of Brotherly Love as Philadelphia hosts its first NL game since 1876. The Quakers, after holding their first spring training at Recreation Park, opened their regular season there bowing to the Providence Grays, 4–3.
- 1884 - In American Association action, Toledo Blue Stockings catcher Moses Fleetwood Walker became the first black to play in the major leagues during a game against the Louisville Eclipse team.
- 1890 - Opening Day in the National League. At West Side Park in Cincinnati, the Chicago Colts spoiled the official opening of the new park by beating the Reds, 4–3, with two runs in the bottom of the ninth inning. This was the first professional game ended in "sudden death," as the old rules required that the full inning be played out even if the team batting last was already ahead.
- 1891 - In front of almost 10,000 fans, Cy Young of the Cleveland Spiders defeated the Cincinnati Reds, 12–3, in the first game ever played in Cleveland's League Park.
- 1898 - The Board of Discipline of the National Baseball League adopted a set of rules to suppress rowdy ball playing. John T. Brush said the resolution, which he proposed, "has worked like a charm."
- 1901 - Herm McFarland of the Chicago White Sox hit the first grand slam in American League history in a 19–9 victory over the Detroit Tigers. His teammate Dummy Hoy also hit a grand slam, in a contest which featured Detroit committing 12 errors, 10 by the infield, to set another AL record, which Chicago will tie on May 6, 1903, against the Tigers.
- 1906 - John Lush of the Philadelphia Phillies pitched a 6–0 no-hitter against the Brooklyn Superbas at Washington Park.
- 1912 - George Sisler, a freshman at University of Michigan, struck out 20 in seven innings. Sisler will start his Hall of Fame career in 1915 with the St. Louis Browns.
- Joe Oeschger of the Boston Braves and Leon Cadore of the Brooklyn Robins each pitched a 26-inning marathon in a 1-1 tie, the longest in major league history. Tony Boeckel and Charlie Pick of Boston each batted 0-for-11 during the deadlock at Braves Field, to set a major league record for hitless at-bats in one game.
- Babe Ruth hit his 50th career home run, and the first for the New York Yankees, in the Boston Red Sox 6–0 loss at the Polo Grounds.
- 1924 - Bill Barrett of the Chicago White Sox stole home twice, in the first and ninth innings, against the Cleveland Indians.
- 1925 - The Philadelphia Athletics introduced another future Hall of Famer, 17-year-old catcher Jimmie Foxx, who pinch-hit a single in the 9–4 loss to the Washington Senators.
- 1927 - Hod Lisenbee of the Washington Senators pitched a shutout in his first major league start, a 6–0 win over the Boston Red Sox.
- 1926 - The legendary pitcher Satchel Paige made his debut in the Negro Southern League. Paige, at 19 age, led Chattanooga to a 5–4 win over Birmingham.
- 1939 - At Comiskey Park, the White Sox defeated the Cubs and Dizzy Dean, 4–1, in an exhibition game to benefit Monty Stratton. The former pitcher, who lost his leg in an off-season hunting accident, tried to pitch in the game and received a new car and nearly $30,000 as a result of the contest.
- 1947 - For the first time, the Cleveland Indians will play all its games at Municipal Stadium. The Indians abandons League Park, where most weekday games have been played. New Cleveland owner Bill Veeck installs an inner fence to cut power alleys from 435 to 365 feet at Municipal Stadium.
- 1949 - Elmer Valo of the Philadelphia Athletics became the first player in American League history to hit two bases-loaded triples in a game. Valo will hit a third bases-loaded triple during the season to tie the league mark set by Shano Collins in 1918.
- 1951 - In the Mother’s Day, Mickey Mantle hit the first home run of his career off Randy Gumpert in an 8–3 victory over the Chicago White Sox at Comiskey Park. In the same game, former Negro Leagues star Minnie Miñoso became the first black player in the history of the White Sox franchise. Miñoso belted a home run in his first major league at-bat off Vic Raschi.
- 1955 - Cleveland Indians starters showed up on a 'pitching clinic' during a doubleheader sweep of the Boston Red Sox at Municipal Stadium. Veteran Bob Feller pitched hitless for 6+ innings and hurled his major league record 12th one-hitter in a 2–0 victory, and in the night cap rookie Herb Score stroke out the first nine batters (for a total of 16) en route to a 2–1 four-hitter victory.
- 1959 - At the age of 39, Early Wynn of the Chicago White Sox pitched a one-hitter shutout, struck out 14, and hit a double and home run for a 1–0 victory over the Boston Red Sox at Comiskey Park.
- 1965 - Los Angeles Dodgers All-Star Tommy Davis broke his ankle sliding into second base. Although Davis will go on to play another 11 seasons, he will never recapture the he displayed prior to the injury. In 1962, Davis led the National League with a .346 batting average and 153 RBI.
- 1968 - Philadelphia Phillies pitcher John Boozer was ejected by umpire Ed Vargo at Shea Stadium for throwing spitballs during his warmup pitches. Boozer is only the second major league pitcher to be ejected from a game for do it.
- 1969 - At Crosley Field, Don Wilson of the Houston Astros pitched his second career no-hitter. Wilson stroke out 15 in downing the Cincinnati Reds, 4–0, one day after Cincinnati pitcher Jim Maloney no-hit the Astros and nine days after Wilson absorbed a 14–0 pounding by the Reds.
- 1973 - At Candlestick Park, the San Francisco Giants scored seven runs with two outs in the ninth inning to beat the Pittsburgh Pirates 8–7.
- Dock Ellis of the Pittsburgh Pirates hit with pitches three batters during the first inning of a game against the Cincinnati Reds, with Pete Rose, Joe Morgan and Dan Driessen being his victims. Ellis, who admitted to intentionally trying to hit each Reds batter that faced him, threw two pitches behind Tony Pérez’ head before walking him and was taken out of the game by Pirates manager Danny Murtaugh while facing the next batter, Johnny Bench.
- Tom Seaver stroke out 16 Dodgers and gave up only three hits in over twelve innings, but the Mets lose in the 14th, 2–1.
- 1975 - Hank Aaron collected four hits and two RBI in the Brewers’ 17–3 win over Detroit. This brings his career RBI total to 2,211, breaking Babe Ruth's published record of 2,209. On February 3, 1976, the Records Committee will revise Ruth's total to 2,204. In actuality, Aaron set the record with 2,205 on April 18, 1975.
- 1978 - Former major league pitcher and controversial book author Jim Bouton began a comeback with the Savannah Braves of the Southern League. The 39-year-old Bouton will eventually earn a promotion to the Atlanta Braves, where he will struggle in a late-season stint.
- 1980 - Bill Madlock of the Pittsburgh Pirates received a 15-game suspension and a $5,000 fine for hitting umpire Jerry Crawford in the face with his glove during a recent game. Madlock will appeal the suspension and continue playing until June 6, when he decides to withdraw his protest.
- 1984 - Dwight Gooden became the first teenager to strike out a least ten players since Bert Blyleven accomplished the feat in 1970. The Mets 19-year old phenom, who will set a major league rookie record with 276 strikeouts, will have a total 15 double-digit strikeout games this year.
- 1985 - Jimmy Key became the first left-handed starting pitcher in 614 games to win a game for the Toronto Blue Jays.
- 1987 - Free agents Ron Guidry (Yankees), Rich Gedman (Red Sox), Bob Boone (Angels) and Tim Raines (Expos) all re-signed with their former clubs on the first day they are allowed to do so. Doyle Alexander (Braves) will re-sign on May 5.
- Rickey Henderson of the Oakland Athletics surpassed Lou Brock as MLB career stolen base leader with his 939th steal in the 7–4 victory over the New York Yankees. Henderson broke the record in the fourth inning, when he stole third base against catcher Matt Nokes.
- Nolan Ryan of the Texas Rangers pitched his seventh no-hitter of his major league career. The 44-year-old Ryan, who defeats the Toronto Blue Jays, 3–0, became the oldest pitcher to hurl a no-hit game. His masterpiece included 16 strikeouts and only two walks. It is also the 209th time he has stroke out 10 or more in a game, and the 26th time putting 15 or more down on strikes.
- At County Stadium, the Milwaukee Brewers defeated the Chicago White Sox in a six-hour, five-minute, 19-inning contest, the longest in American League history since the same two clubs played 25 innings on May 8, 1984. Willie Randolph hit the winning RBI in the 19th.
- 1995 - MLB owners and the Umpires Association reached an agreement on a five-year contract, ending the lockout. Regular umpires will return to work on May 3.
- San Francisco Giants left fielder Barry Bonds became the first player to hit a ball into San Francisco Bay (McCovey's Cove) as the first 'splashdown' home run at Pacific Bell Park helped the Giants to beat the Mets, 10–3.
- With the help of a Quilvio Veras home run, the Braves established a franchise-record 14th straight victory beating the Dodgers, 2–1.
- 2002 - Recording his 321st save for the San Diego Padres, Trevor Hoffman set a new major league record for the most saves for one team surpassing the mark set by Dennis Eckersley with the Oakland Athletics. The long-time San Diego closer, now eighth on the all-time list, was traded as a rookie pitcher by the Florida Marlins as part of the Gary Sheffield deal in 1993.
- In the 6–3 victory over the Marlins at Pac Bell Park, Barry Bonds of the Giants set a major league record by being walked four times intentionally in a nine-inning game. In 1990, Cubs' outfielder Andre Dawson was given five intentional passes in a 16-inning contest against Cincinnati.
- Frank Catalanotto of the Toronto Blue Jays became the first player in franchise history to collect six hits in one game, as he hit five singles and a double helping Toronto to beat the Chicago White Sox, 10–6.
- 2005 - Cy Young Award winner Johan Santana ended his 17-game winning streak in the Minnesota Twins 2–1 loss to the Los Angeles Angels. Santana struck out seven over eight innings and allowed just two hits, but they were solo home runs by Vladimir Guerrero and José Molina.
- 1863 - Frank Foreman, pitcher (d. 1957)
- 1885 - George McQuillan, pitcher (d. 1940)
- 1896 - Heinie Meine, pitcher (d. 1968)
- 1917 - Johnny Berardino, infielder (d. 1996)
- 1919 - Al Zarilla, All-Star outfielder (d. 1996)
- 1948 - Von Joshua, outfielder
- 1954 - Roy Lee Jackson, pitcher
- 1960 - Charlie O'Brien, catcher
- 1964 - José Lind, infielder
- 1966 - Armando Reynoso, pitcher
- 1973 - Rich Butler, outfielder
- 1979 - Brandon Claussen, pitcher