I once answered this question in a newspaper article last century. The sub-editor thought I had made a mistake so added 100 years to the answer. We have been using sugars and honey as a sweetener for millennia. The next sweet agent to get attention was saccharin in 1880 (not 1980, sub-editor).
Saccharin is from the Latin word for sweet. It was first isolated by Ira Remsen and Constantine Fahlberg at Johns Hopkins University in the US. Fahlberg was smart enough to patent the production method and became wealthy through its commercial manufacture in Germany. Remsen and Johns Hopkins never made a cent from saccharin.
Saccharin is cheap to make so it became a sugar substitute during both world wars. My parents remember its taste through the 1940s before sugar became more available.
Saccharin has attracted plenty of attention over the years through mainly negative commentary, in the 1980s especially. It is now widely considered as safe for human consumption after scientific scrutiny, being approved for use in over 100 countries.
Source: That’s the Way the Cookie Crumbles by J Schwarcz (ECW Press, Toronto 2002)