Explain the continuities and changes in territorial holdings from 1900 to present

There was westward expansion from 1900 onward in the American territory that started with Louisiana purchase.

Explanation:

Americans upheld the possibility of abroad extension in the late 1800's on the grounds that they needed to extend exchange and trade to Latin America, to spread majority rules system, to politically impact different nations, and grow so America has a more area.

These were the reasons why America wanted to expand it's territories and expansion of the country in the late eighteenth century more over the Louisiana purchase led to the expansion of the country. The U. S. expanded its territory largely through military conquest. Even purchases from other European powers, such as the Louisiana Purchase and Alaska.