Turns out that Sacagawea's name wasn't originally Sacagawea. It's actually a Shoshoni rendering of the name she was given when she was a captive of the Hidatsas people, tsaka'aka wi'a, a compound of two nouns meaning "bird woman" (the reason for this association is lost to history). When she reunited with the Shoshone, they apparently folk etymologized her name to Sacajawea, which meant "boat puller", with this confusion probably causing the switch from a k/g pronunciation in the center of her name to a j. Lewis and Clark were no help at all in figuring this out, because they wrote down her name with a bunch of inconsistent spellings and personally called her Janey. According to Google Ngram Viewer, usage of the name Sacagawea spiked sharply in the late 1990s, peaking in 2004. My best explanation for this is the US issued a coin bearing her image in the year 2000, and there must've been both a lot of people discussing that and increased awareness of who she was in general.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.