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There's no denying we can't get enough coffee — in fact, two-thirds of Americans wake up with a cup [2] every morning. The energizing drink has been given a long list of beloved nicknames: java, brew, mud, but maybe the most famous is "a cup of Joe." But why do we call coffee "joe"?
The saying is actually inspired by Josephus Daniels, who was the secretary of the US Navy [3] under President Woodrow Wilson from 1913 to 1921. According to Quartz, Josephus Daniels was on a mission to make the Navy more moral [4]. He increased the number of chaplains and came down on prostitution on navy bases, also banning alcohol consumption and instead replacing cocktails and liquor with a suggestion to drink coffee.
In author Lee Craig's biography of Daniels, titled Josephus Daniels: His Life and Times [6], he writes: "As a substitute, stewards increased their purchases of coffee, among other beverages, and Daniels's name became linked to the daily drink of millions around the world [7]. A cup of coffee became disparageingly known as 'a cup of Joseph Daniels,' and as legend has it, this was soon shortened to a 'cup of Joe.'"
Rumour has it, sailors and officers were not happy to be given less booze and more coffee, but the nickname stuck.