1. In 1846, during the Mexican-American War, the Battle of Santa Fe took place on August 19. American troops under the command of General Stephen W. Kearny captured the city without resistance and established control over New Mexico.

2. On August 19, 1879, the Lincoln County War came to a violent end with the death of Billy the Kid's ally, Alexander McSween. McSween, a lawyer and supporter of rival rancher John Tunstall, was killed by members of the opposing faction led by James Dolan.

3. The New Mexico State Fair, one of the largest events in the state, began on August 19, 1938. The fair features agricultural exhibits, livestock shows, carnival rides, concerts, and other entertainment.

4. In 1953, the first atomic cannon was tested at the White Sands Proving Ground in New Mexico on August 19. The cannon fired a 15-kiloton atomic shell, which exploded about seven miles away.

5. On August 19, 2019, the state of New Mexico reached a settlement with several Native American tribes over water rights in the Rio Grande River. The settlement ended a decades-long legal battle over the allocation of water resources in the region.