[2][3] The "Mickey Finn" is most likely named after the manager and bartender of the Lone Star Saloon and Palm Garden Restaurant, which operated on South State Street in the Loop neighborhood of Chicago from 1896 to 1903.
[4][5][6] In December 1903, several Chicago newspapers documented that a Michael "Mickey" Finn managed the Lone Star Saloon and was accused of using knockout drops to incapacitate and rob some of his customers.
The first popular account of Mickey Finn was given by Herbert Asbury in his 1940 book Gem of the Prairie: An Informal History of the Chicago Underworld.
[13][14][15][16][17][18][19] Chemical analysis showed that it contained antimony potassium tartrate,[15] also called "emetic tartar"; which in addition to causing vomiting, headaches, dizziness and depression, can be lethal in large quantities.
Wood sold packets of it for 20 cents[20] and referred to it as "Mickey Finn Powder" in a letter to union bartender John Millian.