South America: The U.S. decides its presence in the Falklands, and this leads to a war with Argentina, gaining the U.S. some land there as well as in the Falklands.
Africa: The Americans, having a bigger navy after deciding to fight for the Falklands, secure trading interests on Madagascar. It later becomes a state.
Asia: One word: Philippines.
Oceania: American interests in Fiji never diminish, and the area ends up under U.S. control permanently.
Europe: Iceland.
Antarctica: Wilkes Land