1. In 1829, the New York State Legislature passed a bill to abolish imprisonment for debt. This was a major step in the reform of the state's criminal justice system.

2. In 1860, the Pony Express began service, with riders carrying mail from Missouri to California. This service helped to connect the East and West coasts of the United States, and played a key role in the expansion of the country.

3. In 1948, the United Nations General Assembly adopted the Universal Declaration of Human Rights, which set out a common standard of rights for all people around the world. The declaration was drafted in part by Eleanor Roosevelt, who was a delegate from the United States.

4. In 1968, civil rights leader Martin Luther King Jr. delivered his final speech, known as the "I've Been to the Mountaintop" speech, at the Mason Temple in Memphis, Tennessee. King was assassinated the next day.

5. In 1973, the Twin Towers of the World Trade Center were officially opened in Manhattan. The towers stood as the tallest buildings in the world until 1974, and became a symbol of New York's economic and cultural importance. They were destroyed in the September 11, 2001 terrorist attacks.