| Date | Place | Ballpark | Event | Ref |
| February 2 | Chicago | | William Hulbert organized the National League of Professional Base Ball Clubs, replacing the National Association of Professional Base Ball Players, which had folded at the conclusion of the 1875 season. Morgan Bulkeley, the owner of the Hartford franchise, is selected as the league's first President. | [1] |
| February 12 | Chicago | | After he joined the Chicago Club as a player, Albert Spalding announced his plan to open a sporting goods retail store in Chicago; known today as Spalding. | [6][7] |
| April 22 | Philadelphia | Athletic Park | The Bostons defeat the Athletics by the score of 6–5, in the first NL game. Joe Borden, pitching under the pseudonym Joe Josephs, is the winning pitcher, and Jim O'Rourke collected the league's first base hit. | [6][8] |
| April 25 | Louisville | Louisville Baseball Park | In Chicago's first National League game, Albert Spalding threw the NL's first shutout as Chicago defeated Louisville by the score of 4–0. Spalding threw another shutout in the Chicagos' second game, on April 25, also against Louisville. | [6][9] |
| May 2 | Cincinnati | Avenue Grounds | Ross Barnes of the Chicagos hit the first NL home run, an inside-the-park home run off pitcher Cherokee Fisher of Cincinnati. | [6][10] |
| May 13 | Hartford | Hartford Ball Club Grounds | The New York Mutuals achieved a triple play in a loss to Hartford. | [6][11][12] |
| May 25 | Philadelphia | Jefferson Street Grounds | The game between Athletic and Louisville ended in a 2–2 tie, the first game to end in a tie in the NL and in major league history. | [6][13][14] |
| May 30 | New York | Union Grounds | In a game between Louisville and Mutual, Louisville right fielder George Bechtel committed three of the nine errors that led to his team's defeat. Louisville's ownership suspected that he intentionally "fixed" the game by intentionally committing errors to ensure a winning bet for himself and other gamblers. Management intercepted a wire dated June 10, in which Bechtel conspired to lose the game that day. Bechtel refused to resign when confronted with the evidence, so Louisville banished him from the team. | [15] |
| June 14 | Philadelphia | Jefferson Street Grounds | George Hall and Ezra Sutton of Athletic each hit three triples in a 20–5 victory against Cincinnati, the only time teammates have accomplished this feat. | [6][16] |
| June 17 | Philadelphia | Jefferson Street Grounds | In a 23–15 victory over Cincinnati, George Hall of Athletic becomes the first major league player to hit two home runs in a single game. | [16][17] |
| June 27 | Chicago | 23rd Street Grounds | Davy Force of Athletic collects six hits in six at bats in a 14–13 victory against Chicago and Albert Spalding. He is the first major leaguer to collect six hits in a nine-inning game. | [6][9][18] |
| July 15 | St. Louis | Grand Avenue Park | George Bradley of St. Louis pitches the first no-hitter in MLB history, a 2–0 victory against Hartford. It is the second no-hitter recorded in professional play, after Joe Borden's on July 28, 1875. | [19][20] |
| July 25 | Chicago | 23rd Street Grounds | Cal McVey of the Chicagos collects six hits for the second consecutive nine-inning game. He has totaled 15 hits in the last three games, and 18 hits in the last four, both records. After collecting two more hits on July 27, and four more on July 29, McVey will have tied his own record with 18 hits in a four-game stretch. | [6][9] |
| August 4 | Louisville | Louisville Baseball Park | Trailing Chicago with rain looming, the Louisvilles stall the game by committing error after error until the umpire rules the game a forfeit. The game result would later be removed from the official league standings. | [6] |
| August 21 | St. Louis | Grand Avenue Park | In the ninth inning, and the score tied 6–6, of a game between Chicago and St. Louis, a St. Louis batter hit the base-runner coming from third base with batted ball. The umpire ruled that the runner was allowed to score, so Chicago left the field in protest. The umpire then awarded the game to St. Louis. | [21] |
| September 5 | New York | Union Grounds | George Bradley of St. Louis records his 16th shutout of the season in a 9–0 win over Mutual. This season total of 16 shutouts has since been tied, by Grover Cleveland Alexander, of the Philadelphia Phillies in 1916. | [19][22] |
| September 11 | Philadelphia | | The Philadelphia Athletic Club informs the league office that it will be unable to make its last western road trip due to financial trouble. The owner of the Athletics suggested that the Chicago and St. Louis Clubs play additional games in Philadelphia, take a larger than normal portion of the gate receipts, so they raise enough money to finish their schedule, which was denied. | [6] |
| September 16 | New York | | The Mutual Club of New York announces to the league office that it will not make its final western road trip of the season due to lack of funds. | [6] |
| September 26 | Chicago | 23rd Street Grounds | The Chicago Club clinches the first National League pennant with a 7–6 win over Hartford. | [6][9] |
| October 23 | Chicago | | The Chicago Tribune published the year-end player statistics, one of which would be the newly created, batting average; the first known instance of this statistic being published. | [6] |
| December 10 | Cleveland | | During the NL's Winter Meetings, it was announced that William Hulbert was elected President of the league, and that the Philadelphia Athletics and the New York Mutuals were expelled for failure to complete their required schedule in the 1876 season. | [23] |
