Which land purchase doubled the size of the United States in 1803?

The Louisiana Purchase was a significant event in American history that occurred in 1803, resulting in the acquisition of approximately 828,000 square miles of territory from France. This land purchase effectively doubled the size of the United States at the time, greatly expanding its borders westward.

The motivations behind this purchase were rooted in the desire for more land for agriculture and settlement, as well as the strategic importance of controlling the Mississippi River and its tributaries for trade. The deal was negotiated by President Thomas Jefferson, who recognized the immense potential of the land. The acquisition of such a large expanse of territory facilitated westward expansion and played a critical role in shaping the future of the nation.

Comparatively, the other choices represent different periods and contexts in American history. The Gadsden Purchase took place in 1853 and involved a smaller land area primarily for the construction of a southern transcontinental railroad. The Alaska Purchase occurred in 1867, adding territory from Russia, and the Oregon Territory was settled through diplomacy and conflict in the mid-1800s, none of which had the immediate impact on the size of the nation as the Louisiana Purchase did.