Ferdinand Magellan discovered Guam in 1521. Located in the western Pacific Ocean, the island became an important stopover for Spanish ships for 200 years. It became an American territory in 1898 as a result of the Spanish-American War.
Spanish conquered Aztecs in 1521. The city of Tenochtitlan fell to Hernan Cortez and his allies. Cortez had arrived on the shores several months before. Montezuma, leader of the Aztecs, felt Cortz might be one of their gods, Quetzalcoatl. Montezuma made the fighters feel welcome, but ultimately the Spanish turned on the Aztecs. Children can read some great background information at: Aztecs.