MAP ACTIVITY Map 12.5 Territorial Expansion by 1860 Less than a century after its founding, the United States spread from the Atlantic seaboard to the Pacific coast. War, purchase, and diplomacy had gained a continent. READING THE MAP: List the countries from which the United States acquired land. Which nation lost the most land because of U.S. expansion? CONNECTIONS: Who coined the phrase manifest destiny? When? What does it mean? What areas targeted for expansion were the subjects of debate during the presidential campaign of 1844?