1894 - Jouett Meekin of the New York Giants becomes the only pitcher to hit three triples in a game. The Giants beat the Cleveland Spiders 12-11 in the second game of a doubleheader.
1896 - Washington and Philadelphia combine for 73 hits in a doubleheader. Washington wins the first game 13-8 and Cleveland takes the second 15-14.
1905 - The Philadelphia A's play 20 innings against Boston in the second game of a doubleheader and don't draw a walk, an AL record. The A's win the game anyway, 4-2. Cy Young takes the loss for Boston, pitching all 20 innings.
1907 - The Tigers and Browns combine to hit 12 triples in a doubleheader. Without looking it up, I'm guessing there was a big crowd and weird ground rules. The Tigers win both games. The Tigers are in fourth place, 6 1/2 games out, at the end of the day. This would be the largest margin overcome on the 4th of July by any AL pennant winner.
1908 - Hooks Wiltse of the Giants throws the first extra-inning no-hitter in NL history, beating the Phillies 1-0. Wiltse retired the first 26 batters before hitting the opposing pitcher George McQuillan with a pitch.
1913 - Smoky Joe Wood of Boston becomes the second pitcher to hit two doubles in an inning in the morning game of a doubleheader against Philadelphia.
1918 - The NL features a record-tying three 1-0 games. The Cubs sweep a doubleheader in St. Louis by a pair of 1-0 scores. The Pirates beat the Reds for the third one.
1939 - Boston and Philadelphia (AL variety) combine for an AL record 172 ABs in a doubleheader (with no extra innings involved). Jim Tabor of the Red Sox hits four home runs (an AL record for a doubleheader) and drives in 10 (also an AL record). Boston won 17-7 and 18-12. The 54 total runs are tied for the most in MLB history. The 65 total hits are an AL record as are the 49 RBI.
1940 - George Case of Washington becomes one of four AL players to have 9 hits in a doubleheader. The Senators swept a pair from Philadelphia.
1945 - The Cleveland Indians become the first team in major league history to play nine innings in the field and not record an assist. It happens in the first game of a doubleheader that Cleveland wins over the Yankees 4-2. Cleveland pitcher Steve Gromek gets 21 Yankees to make outs in the air, strikes out four, and two other unassisted outs (which presumably were ground outs to first.)
1948 - Ted Williams becomes the first of eight AL players to have three plate appearances in an inning. Williams does it in a 14-run 7th inning against the A's. Boston wins 19-5. Of the eight ALers to have three plate appearances, all but one of them played for the Red Sox. (Darryl Hamilton is the other guy.)
1951 - Ralph Kiner of Pittsburgh ties an NL record by driving in seven runs over two consecutive innings. It's in the second game of a doubleheader against the Reds. The Pirates win 16-7 in a game shortened to 5 1/2 innings.
1955 - In the first game of a doubleheader, the Yankees and Red Sox combine to send up five different pinch hitters who struck out. The Red Sox win 4-2 in 2:54, an eternity for that era and preparing fans for the horrors that would await them in the 21st Century.