1. 1770: Marie Antoinette, Queen of France, attended the Paris premiere of the play "Zaire" by Voltaire at the Comédie-Française.
2. 1775: The American Revolutionary War began with the Battles of Lexington and Concord in Massachusetts.
3. 1782: John Adams secured the recognition of the United States as an independent government by the Dutch Republic.
4. 1839: The Treaty of London recognized Belgium as an independent and neutral country.
5. 1861: The Baltimore riot of 1861 marked the first bloodshed in the American Civil War as Union troops clashed with southern sympathizers.
6. 1897: The first Boston Marathon was held, with John J. McDermott winning the race.
7. 1927: Mae West was sentenced to 10 days in jail for obscenity due to her play "Sex."
8. 1943: The Warsaw Ghetto Uprising began against the Nazi occupation of Poland.
9. 1956: Actress Grace Kelly married Prince Rainier of Monaco.
10. 1960: Baseball player Eddie Mathews hit his 500th career home run.
11. 1971: The Soviet Union launched the Salyut 1, the first space station.
12. 1989: A gun turret explosion aboard the USS Iowa killed 47 sailors.
13. 1993: The 51-day siege of the Branch Davidian compound near Waco, Texas, ended with a fire that killed 76 people.
14. 1995: A truck bomb destroyed the Alfred P. Murrah Federal Building in Oklahoma City, killing 168 people.
15. 1997: The Red River Flood devastated Grand Forks, North Dakota, and East Grand Forks, Minnesota.
16. 2005: Cardinal Joseph Ratzinger was elected as Pope Benedict XVI.
17. 2013: A bombing at the Boston Marathon killed three people and injured hundreds.
18. 2014: A ferry capsized off the coast of South Korea, resulting in over 300 deaths.
19. 2019: The final episode of the TV series "Game of Thrones" aired, concluding the series.
20. 2020: Bernie Sanders suspended his campaign for the Democratic nomination for President of the United States.

These events highlight a range of historical, cultural, and political moments that have occurred on April 19 over the years.