Zachary Seward writing for Quartz on the origin of coffee being called “Joe” comes from Josephus Daniels:

As it turns out, the use of joe as slang for coffee dates to the World War I era. It was then that Daniels, who started his career as a newspaper publisher in North Carolina, became secretary of the Navy under president Woodrow Wilson. As recounted in a new biography, Daniels tried to imbue the navy with a strict morality. He increased the number of chaplains, discouraged prostitution at naval bases, and, most controversially, banned the consumption of alcohol.

“As a substitute, stewards increased their purchases of coffee, among other beverages,” writes Lee Craig in the new book, “and Daniels’s name became linked to the daily drink of millions around the world. A cup of coffee became disparagingly known as ‘a cup of Joseph Daniels,’ and as legend has it, this was soon shortened to a ‘cup of Joe.’”