What was yjhe idea that the US must expand from ocean to ocean?

Answer 1

The idea that the U.S. must expand from ocean to ocean is known as Manifest Destiny, a 19th-century belief that American settlers were destined to expand across North America. This ideology was rooted in the conviction that it was both justified and inevitable for the U.S. to spread its influence and democracy. Manifest Destiny fueled westward expansion, resulting in territorial acquisitions such as the Louisiana Purchase and the annexation of Texas, and significantly impacted relations with Native Americans and other nations.