1. The Louisiana Purchase (1803)
In 1803, the U.S. acquired the Louisiana Territory from France, instantly doubling its landmass. This monumental deal—for $15 million—remains one of history’s most significant land acquisitions. The newfound territory not only fueled westward expansion, but also unlocked vast natural resources that would power American industry and agriculture.
Unlike other land deals such as Alaska’s purchase, the Louisiana Purchase became a springboard for American growth, setting the stage for economic might and national unity that would shape the country for generations.
