1. Wyoming Becomes A State: On September 1, 1890, Wyoming became the 44th state of the United States. Before that, it was a territory for almost 25 years. This significant milestone in Wyoming's history marked the end of a long journey to statehood and started a new chapter in Wyoming's history.

2. The Opening of the University of Wyoming: On September 1, 1887, the University of Wyoming opened its doors to students for the first time. It was established as a land-grant university, which means it was founded with the support of federal land grants. The university has gone on to become one of the leading educational institutions in the state.

3. The Relocation of the Heart Mountain Internment Camp: On September 1, 1942, the Heart Mountain Internment Camp was relocated to its new location in Wyoming. During World War II, over 14,000 Japanese Americans were forced to live in internment camps across the country, and Heart Mountain was one of them.

4. The Establishment of Yellowstone National Park: Although not specifically related to September 1, it's worth noting that Wyoming is home to the first national park in the United States. Yellowstone National Park was established on March 1, 1872, and covers parts of Wyoming, Montana, and Idaho. It's an iconic destination for tourists and one of the state's most important landmarks.

5. The Cheyenne Frontier Days: The Cheyenne Frontier Days is an annual rodeo and western celebration held in Cheyenne, Wyoming, every July. However, its origins date back to September 1, 1897, when the first Frontier Days celebration was held. It has since grown into one of the largest and most well-known rodeos in the world and is an important cultural event for Wyoming.