New Mexico became the forty-seventh state of the United States in 1912. Although New Mexico is one of the youngest states, it boasts some of the oldest American structures. Spaniards traveled on El Camino Real (the Royal Highway) in 1581; and Santa Fe, the capital, was built in 1609 or 1610. Children could visit an Internet site at: New Mexico. Idea: Children could create some math problems regarding how long ago New Mexico’s treasures were created.