Final answer:
The Louisiana Purchase gave the United States all or part of 18 current states and two Canadian provinces, effectively doubling the size of the nation and opening up new territories for settlement and expansion.
Step-by-step explanation:
The Louisiana Purchase, which took place in 1803, gave the United States all or part of 18 current states and two Canadian provinces. This acquisition effectively doubled the size of the nation and opened up vast new territories for settlement and expansion.
Under the Louisiana Purchase, the United States gained control over the Mississippi River and the port of New Orleans, as well as the land west of the Mississippi River, including present-day Arkansas, Missouri, Iowa, and Minnesota. The purchase also included parts of present-day Montana, North Dakota, South Dakota, Nebraska, Oklahoma, Kansas, Colorado, Wyoming, and Louisiana. In addition, the United States acquired parts of what is now the Canadian provinces of Alberta and Saskatchewan.
The Louisiana Purchase was not only important for its territorial expansion but also for its impact on the development of the United States as a continental nation. It paved the way for further westward expansion, the exploration and settlement of new lands, and the development of trade and commerce across the continent.