Westward Expansion
The United States didn't always look how it does today. Our country gradually expanded from the original 13 colonies.
It began in the east with the 13 original colonies and, gradually, pioneers and settlers explored westward. As they travelled west, they started new cities and towns.
Two of the first explorers of the new land were Lewis and Clark. They were guided by Sacagawea, a Native American who knew the land.
By the mid 1800s, pioneers set out in covered wagons pulled by oxen to start new towns in the west. They travelled thousands of miles in harsh conditions to start new lives in central and western United States, like Missouri, Colorado, California, and Oregon. It was very dangerous and many did not survive the journey.