Manifest Manhood and the Antebellum American EmpireThe U. S. Mexico War (1846 1848) brought two centuries of dramatic territorial expansionism to a close, and apparently fulfilled America's Manifest Destiny. Or did it? Even as politicians schemed to annex new lands in Latin America and the Pacific, other Americans aggressively pursued expansionism independently. In fact, an epidemic of unsanctioned attacks by private American mercenaries (known as filibusters) occurred between 1848 and 1860 throughout