1. On September 19, 1905, notorious outlaw Tom Horn was hanged in Cheyenne for the murder of 14-year-old Willie Nickell. Horn had been a cavalry scout, a Pinkerton detective, and a rustler before becoming a hired assassin. Over the course of his criminal career, he claimed to have killed as many as 22 men.

2. The Wyoming State Capitol building was dedicated on September 19, 1917. The Beaux-Arts style building had been under construction for several years and cost an estimated $1.25 million. Today, it remains an iconic landmark in the heart of Cheyenne.

3. The first coal mine in Wyoming was established on September 19, 1867, near the town of Carbon. The mine, known as the Carbon Creek mine, was owned and operated by the Wyoming Coal and Mining Company. It was only the first of many coal mines to open in Wyoming, which would go on to become a major coal-producing state.

4. On September 19, 1875, famous artist Albert Bierstadt visited Yellowstone National Park and sketched some of its most iconic features, including Old Faithful and the Grand Prismatic Spring. Bierstadt's paintings and sketches helped introduce the beauty and grandeur of Yellowstone to the rest of the world.

5. The University of Wyoming was founded on September 19, 1886, when President Chester A. Arthur signed a bill establishing the school. Originally known as the Wyoming State Normal School, it was primarily a teacher training institution. Today, the University of Wyoming is a comprehensive research university, with an enrollment of over 12,000 students.