When Sacagawea was born, George Washington was president, and the country consisted of 13 states huddled along the Atlantic Coast. But all that would be changing very quickly.
Thomas Jefferson, who became president in 1801, envisioned a nation that stretched from the Atlantic to the Pacific. To the Native Americans who had lived on this land for thousands of years, he gave little thought. But the European nations that had claimed various parts of the West worried him. He was especially concerned that France had recently acquired from Spain a huge parcel of land called Louisiana. The important port of New Orleans was at the southern tip of this land, so Jefferson sent a representative to France to try to get the French leader, Napoléon, to sell New Orleans to the United States. Jefferson got way more than he bargained for.

▲ Napoléon’s dream was to build an empire in Europe and beyond. But he didn’t have the resources to do battle in both Europe and America. So, much to Jefferson’s surprise, Napoléon offered to sell the U.S. not only New Orleans but all of the Louisiana Territory at bargain rates. Thus, in 1803, for $15 million (about four cents per acre), the U.S. doubled its territory.

◀ It wasn’t only France that worried Jefferson. Spain, Russia, and Britain all claimed territory in the U.S. and Canada. In the summer of 1793, Scotsman Alexander Mackenzie had traveled from central Canada to the Pacific Coast, laying claim to the Pacific Northwest for Britain. Jefferson needed to put a U.S. presence in the West, and fast!

▲ To explore the new territory, Jefferson chose his secretary, Meriwether Lewis. As his co-captain, Lewis picked William Clark, with whom he had served in the army. The two captains assembled a group of volunteers and collected the necessary supplies. They would sail up the Missouri River as far as possible, and then continue on in search of a land route to the Pacific. They would make maps and establish friendly relations with the Native Americans they met. They would also collect specimens of new animal and plant life, and record their observations.


◀ Lewis and Clark decided the expedition should spend the winter months near the friendly Mandan and Hidatsa villages. This happened to be where Sacagawea and Charbonneau made their home.

▲ Corps of Discovery Expedition
On May 14, 1804, the Lewis and Clark expedition set off from Wood River, Missouri. The expedition was officially known as the Corps of Discovery. It had some 40-odd members, including Clark’s slave, York, and Lewis’s huge Newfoundland dog, Seaman.