•european powers stopped colonizing the western hemisphere. • the u. s. agreed to leave europe's established colonies in the western hemisphere alone. the box above describes a. why the protocol of peace led to the end of the spanish-american war. b. how the treaty of ghent ended disagreements from the war of 1812. c. the standards of peace that canada and the u. s. agreed to have with each other. d. significant outcomes that resulted from the monroe doctrine.