Who were some of the early pioneers?

Some early pioneers include figures like Lewis and Clark, who explored the American West in the early 1800s, mapping uncharted territories and establishing routes for future settlers. John C. Frémont, known as "The Great Pathfinder," also played a significant role in mapping the West during the mid-1800s. Additionally, women like Sacagawea, who accompanied Lewis and Clark, were vital in facilitating communication and navigation. These pioneers contributed significantly to the westward expansion of the United States.