Thomas Edison's most famous invention
I don't think many people would have guessed it was the job interview. It was a big surprise to me.
From: History Facts
"Although Thomas Edison was awarded 2,332 worldwide patents as an inventor, one of his lasting contributions to modern society was not proprietary: the job interview. Edison was not just a prolific inventor — he was also a businessman in charge of an industrial empire. His corporation, Thomas A. Edison, Inc., employed more than 10,000 workers at dozens of companies. Edison wanted employees who could memorize large quantities of information and also make efficient business decisions. To find them, he devised an extensive questionnaire to assess job candidates’ knowledge and personality."