1. On July 21, 1868, Nevada became the 36th state in the United States. The state is known for its rich history in silver mining and as a popular tourist destination, with attractions such as the Hoover Dam and Lake Tahoe.

2. In 1908, the Reno Chamber of Commerce was founded on July 21, with the mission to promote economic development in the city. Reno has since become a popular destination for gambling, entertainment, and outdoor activities.

3. July 21, 1931 marked the beginning of legalized gambling in Nevada. The state legalized gambling as a way to generate revenue during the Great Depression, and it quickly became a popular attraction for visitors.

4. In 1954, the Nevada Test Site conducted its first nuclear weapons test on July 21. Located about 65 miles northwest of Las Vegas, the test site played a key role in the development of nuclear weapons during the Cold War.

5. On July 21, 2005, NASA's Deep Impact spacecraft successfully collided with the comet Tempel 1, providing scientists with valuable data about comets and their composition. The spacecraft was designed and built in part by the University of Nevada, Las Vegas.