Jean Baptiste Charbonneau was the son of Sacagawea and her French Canadian husband Toussaint Charbonneau, born while they were members of the Lewis and Clark Expedition; expedition co-leader William Clark nicknamed him Pomp or Pompy. Pompeys Pillar on the Yellowstone River in Montana is named after him, and his image can be found on the Sacagawea dollar coin; he is the only child ever depicted on United States currency. Wikipedia
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