What was the role of the federal government in the acquisition of the west?

The federal government played a dominant role in acquiring the west of what is now the United States.  The federal government acquired all of the land west of the Mississippi by treaty, war, or purchase.

The federal government started to acquire land west of the Mississippi with the Louisiana Purchase of 1803.  When the government purchased the Louisiana Territory, it doubled the country’s land area.  The new territory included all of the land in the...

The federal government played a dominant role in acquiring the west of what is now the United States.  The federal government acquired all of the land west of the Mississippi by treaty, war, or purchase.

The federal government started to acquire land west of the Mississippi with the Louisiana Purchase of 1803.  When the government purchased the Louisiana Territory, it doubled the country’s land area.  The new territory included all of the land in the Mississippi River basin up to the crest of the Rocky Mountains.  All of this was bought from France for about $15 million.

Next, the federal government acquired the land that is now the Southwest of the US.  Most of this land was acquired through war.  The US took most of this land from Mexico after the war with that country in the 1840s.  Technically, the US got Texas not through the war but by annexing the area, which had declared independence from Mexico about ten years earlier. 

The federal government completed the acquisition of the Southwest in 1853.  In that year, the government bought land that is known as the Gadsden Purchase from Mexico.  This was land that is now in New Mexico and Arizona.  It was bought for the purpose of building a transcontinental railroad.

Finally, the federal government acquired the Oregon Territory in 1846.  This land had been jointly held by the US and Great Britain.  In 1846, the federal government struck a deal with Britain to divide the territory, with the boundary being set at the 49th parallel.  In these ways, the federal government was the entity that acquired all of the lands of the American West.