African-American Willis Johnson of Cincinnati, Ohio, patented an improved the mechanical egg beater (U.S. pat# 292,821) on February 5, 1884. The beater was made up of a handle attached to a series of spring-like whisk wires used to help mix ingredients. Prior to his eggbeater, all mixing of ingredients was done by hand and was quite labor-intensive and time-consuming.

In fact, what Willis Johnson had really invented was the early mixing machine and not just an egg beater. His device was not intended for eggs alone. Johnson had designed his egg beater and mixer for eggs, batter, and other baker's ingredients. It was a double-acting machine with two chambers. Batter could be beaten in one section and eggs could be beaten in another section, or one section could be cleaned while the other section could continue beating.

Bellis, Mary. "Willis Johnson - Egg Beater." ThoughtCo, Jan. 29, 2020, thoughtco.com/willis-johnson-egg-beater-4072139.