1956: Liquid Paper.

A bad typist’s best friend was invented, not surprisingly,  by a typist. Bank secretary Bette Nesmith Graham, whipped up the original formula in her own kitchen, using tempura paint.

She might never have been recognized as the inventor of the product, had she not made a mistake at work and been fired!  She used her free time to develop and launch her product, under the name “Mistake Out.” which was later changed to “Liquid Paper.”  

She initially tried to sell her invention to IBM, but it passed. Gillette bought it 1979 for $47.5 million. Before computers, liquid paper was the first practical way to quickly correct an error, making it easier for school children and office professionals alike to be sloppier writers.