Sacajawea is from the Lemhi Shoshone Sacajawea — possibly bird woman (Hidatsa: tsakáka wía) — though etymology remains debated among Shoshone + Hidatsa scholars. Sacajawea (c. 1788-1812) was a Lemhi Shoshone woman who became the interpreter + guide for the Lewis and Clark Expedition (Corps of Discovery, 1804-1806) — widely considered one of the figures of American exploration history. Featured on the U.S. circulating coin.
Sacajawea does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Sacajawea reduce to 1, The Leader. This is a traditional interpretive system, not a factual claim about the name.