Final answer:
James Oglethorpe secured friendship with the Yamacraw Indians, particularly with the help of Mary Musgrove, to found the city of Savannah.
Step-by-step explanation:
James Oglethorpe gained the friendship of Tomochichi and the Yamacraw Indians through the intermediary efforts of Mary Musgrove, who played a crucial role in bridging cultural differences and facilitating communication. As a person of both British and Yamacraw descent, she helped Oglethorpe and the Yamacraw to understand each other, which was instrumental in the peaceful founding of Savannah. Oglethorpe's intent to create a buffer zone between the Carolinas and Spanish holdings in Florida, as well as his subsequent construction of forts like Fort Frederica, highlighted the strategic importance of maintaining alliances with local native peoples.