The word milkshake was first used, in print, in 1885, but milkshakes were originally sold in bars as a cure for hangovers. It was like eggnog, made with eggs, cream, sugar and whisky.
(The milkshake as we know it today didn't appear until 1922, at the Chicago Walgreen’s pharmacy. they whisky had gone and two scoops of vanilla ice cream were added to “malted milk”: a mixture of milk, chocolate, and malt powder designed for children and invalids.
By the 1930s, milkshakes were a popular drink at malt shops in the US, which were the "typical soda fountain of the period. In the UK they were known as milk bars, and they were encouraged by the Temperance Society, as a morally acceptable alternative to the pub, which is ironic when you realise how the milkshake actually started.)
