Guam History and Chamorro Heritage Day is observed in Guam on the first Monday in March. Originally known as Guam Discovery Day, this national public holiday commemorated the discovery of Guam by Portuguese explorer Ferdinand Magellan on March 6, 1521. Established as a public holiday in 1970, the focus of the celebration has shifted over time to acknowledge the impact of European colonization on the indigenous Chamorro people. The holiday now aims to celebrate the history of Guam from ancient times to the present, promote the preservation of Chamorro culture, and support Chamorro self-determination. On this day, Guamanians are encouraged to educate their children about their rich heritage and instill core values such as respect, reciprocity, community, and love for one another.