How did the U.S. gain control of Guam?

The U.S. gained control of Guam as a result of defeating Spain in the Spanish-American War in 1898. This conflict arose from ongoing tensions regarding American intervention in Cuba's fight for independence from Spain. The war marked a turning point for the United States, as it sought to assert its influence over former Spanish territories.

As part of the Treaty of Paris, which formally ended the war, Spain ceded Guam along with Puerto Rico and the Philippines to the United States. This acquisition was significant not only for its strategic location in the Pacific but also for establishing the U.S. as a global power with colonial possessions.

The other options do not accurately reflect historical events surrounding Guam’s acquisition. There was no purchase involved nor any prior military colonization directly related to Guam. Furthermore, there was no treaty with Japan related to the control of Guam, as Japan was not involved in the negotiations or subsequent treaty that transferred control from Spain to the United States. Thus, the correct answer highlights the military and diplomatic outcomes of the Spanish-American War that led to the U.S. acquisition of Guam.