From Wiki

"Aspartame was discovered by accident in 1965 by James M. Schlatter, a chemist working for G.D. Searle & Company in Skokie, Illinois. Schlatter had synthesized aspartame as an intermediate step in generating a tetrapeptide of the hormone gastrin, for use in assessing an anti-ulcer drug candidate.[59] He discovered its sweet taste when he licked his finger, which had become contaminated with aspartame, to lift up a piece of paper.[11][60] Torunn Atteraas Garin participated in the development of aspartame as an artificial sweetener.[61]"
NutraSweet Company



"In 1985, Monsanto bought G.D. Searle,[70] and the aspartame business became a separate Monsanto subsidiary, NutraSweet. In March 2000, Monsanto sold it to J.W. Childs Associates Equity Partners II L.P.[71][72] European use patents on aspartame expired beginning in 1987, with the US patent following suit in 1992.[73]"