An illiterate man invented a full writing system from scratch

Sequoyah, a Cherokee silversmith who could not read or write in any language, spent about a decade developing a syllabary of 86 characters representing every syllable in spoken Cherokee. After the Cherokee Nation adopted it in 1821, most of the population became literate within just a few years, one of the fastest voluntary literacy shifts on record.

— Sequoyah, Cherokee syllabary — Adopted by the Cherokee Nation, 1821