1. 1865: The United States Congress passed the 13th Amendment to the Constitution, abolishing slavery.

2. 1950: U.S. President Harry S. Truman announced the decision to develop the hydrogen bomb.

3. 1961: Ham the chimpanzee became the first hominid in space, aboard the Mercury-Redstone 2 spacecraft.

4. 1971: Astronauts Alan Shepard, Edgar Mitchell, and Stuart Roosa launched aboard Apollo 14, marking the third manned mission to the Moon.

5. 2000: Alaska Airlines Flight 261 crashed into the Pacific Ocean, killing all 88 people on board.

6. 2010: The Burj Khalifa in Dubai, the tallest building in the world, was officially opened.