1. On April 15, 1912, New Mexico was still a territory and not yet a state. However, the state's future was being discussed in Congress, and it was on this day that the House of Representatives voted in favor of granting statehood to New Mexico.

2. In 1941, April 15 marked the dedication of the new Carlsbad Caverns National Park Visitors Center. This center was built to accommodate the growing number of visitors to the park and features exhibits and displays about the natural history of the area.

3. On April 15, 1969, a large-scale riot erupted at New Mexico State Penitentiary in Santa Fe. The riot was one of the deadliest in U.S. history, resulting in the deaths of 33 inmates and the injury of many others.

4. In 1976, April 15 was designated as New Mexico Day, a day to celebrate the history, culture, and people of the state. Each year, communities throughout New Mexico hold special events and activities to commemorate the day.

5. Finally, on April 15, 1997, the first exhibit of the International UFO Museum and Research Center opened in Roswell, New Mexico. This museum is dedicated to the study of UFO sightings and other unexplained phenomena, and it has become a popular tourist attraction in the state.