Well they hired her husband to translate and they took her along too.
They needed a translator.
Lewis and Clark hired a French-Canadian fur trapper named Toussaint Charbonneau to serve as their interpreter. Charbonneau's Shoshone wife, Sacagawea, also played a crucial role as an interpreter and guide during the expedition.
When Lewis and Clark wintered at the present site of Bismarck, North Dakota, there they met Sacagawea and her husband in 1804. Toussaint Charbonneau was interviewed to interpret Hidatsa for the Lewis and Clark expedition, but Lewis and Clark (esp. Clark) were not overly impressed with him. However, Sacagawea his wife spoke Shoshone and Hidatsa, so they hired Charbonneau on November 4, and he and Sacagawea moved into Fort Mandan a week later. Sacagawea was 16 or 17 at this time.
Sacagawea wouldn't have been known for her famous expedition that she lead Lewis and Clark on
Lewis, Clark, Sacagawea's Husband, Sacagawea, 45 members, and bunch of People in there.
Sacagawea translated for Lewis and Clark.
sacagawea,lewis,clark,thomas jefferson
lewis and clark!
Lewis and Clark
Sacagawea
Actually, he joined the expediton when Lewis and Clark found them.(Toussaint and Sacagawea)
she traveled with Lewis and clark