The Nation Expands
When the United States won its independence from Great Britain at the end of the Revolutionary War, the country nearly doubled in size. The Treaty of Paris, signed with the British in 1783, provided for the expansion of the young nation west to the Mississippi River.
After 1783, the United States gained new land from European countries, neighboring countries (such as Mexico), and Indian tribes. This was done through purchases (paying for it), wars and treaties, and the forced removal of Indian tribes from the lands they had occupied for thousands of years.
The 13 original British colonies became the country's first states, but they were not the same size and shape as they are today. It took more than 176 years — from 1783 to 1959 — for all 50 states to become part of the United States of America.