1. The Denver & Rio Grande Railroad began operations in Colorado on May 19, 1871. This railroad played a significant role in the state's development by connecting mining towns and agricultural communities, as well as transporting goods and people.

2. On May 19, 1896, Adolph Coors opened the Coors Brewing Company in Golden, Colorado. Coors became one of the largest breweries in the country and helped establish Colorado as a major beer-producing state.

3. The Pueblo Steel Strike began on May 19, 1919, with approximately 10,000 steelworkers walking off the job to demand better pay and working conditions. The strike lasted for 94 days and resulted in significant violence, including the Colorado National Guard killing two strikers.

4. On May 19, 1934, the first prehistoric trackways were discovered near Picketwire Canyon in southeastern Colorado. These tracks were made by dinosaurs over 150 million years ago and are considered some of the most extensive and best-preserved dinosaur trackways in the world.

5. The first female attorney in Colorado, Mary Lathrop, was admitted to the state bar on May 19, 1896. Lathrop went on to become a prominent attorney and advocate for women's suffrage and legal rights.