MAY 14

Meriwether Lewis and William Clark were sent by President Thomas Jefferson to explore the Louisiana Purchase territory, and to find a water route to the west coast. It took two and a half years, and they couldn't have done their job without the help and guidance of Sacagawea. She was a 16-year-old Shoshone woman who was married to a French explorer and trader, Toussiant Charbonneau, who also went on the expedition.

Sacagawea had been kidnapped at a young age, and sold to Charbonneau who made her his wife. She was a young teenager, and just before the journey began, had a baby named Jean Baptiste Charbonneau. Sacagawea carried this baby on her back for most of the expedition. She served as an interpreter, but just having a woman on the trip made life easier and less dangerous for the group of men exploring uncharted territory. Sacagawea saved important papers when a boat capsized, helped negotiate the purchase of a horses from a Shoshone tribe, and even found her brother along the journey who she hadn't seen since she was kidnapped years before. Her brother, Cameahwait, was now a chief of a Shoshone tribe.

It is unclear where and when Sacagawea died. Some say her death was as early as 1812 at the age of 25, others say it was as late as 1884 at the age of 95. We do know that her son Jean Baptiste, was taken into the care of William Clark in St. Louis, MO, in 1809. The boy stayed with Clark and received an education. After graduation, he spent six years living in Europe. Upon his return, he worked as a hunter and trapper, then went out west as part of the Gold Rush. He died at the age of 61 in 1866, while on an expedition.

In 2000, Sacagawea and Jean Baptiste were commemorated on a US dollar coin.

There are many National landmarks that celebrate the Lewis and Clark expedition, including the Lewis and Clark National Historic Trail, which covers 4,500 miles and 16 states. There is also the Lewis and Clark National History Park in Oregon, and the Gateway Arch in St. Louis, MO, where the expedition began.

You can learn more about the Lewis and Clark expedition by watching the BrainPop, or by reading this Nat Geo Kids article, and you can learn more about Sacagawea by watching a TedTalk video about her.