Jokers Session

It is believed that the term "Joker" comes from a mispronunciation of Jucker, the German/Alsatian name for the game Euchre. The card was originally introduced in about 1860 for games of that family to be used as the highest trump. Catherine Perry Hargrave documents jokers from 1862 and 1865 in her book A History of Playing Cards. The 1862 card has a tiger on it and the label "Highest Trump", while the one from 1865 is inscribed "This card takes either Bower" and "Imperial Bower", or "Highest Trump Card".
An alternate theory is that the Joker was originally developed for the game Poker as a wild card; however, this is largely discredited in favor of the Euchre theory. Confusion on this issue may stem from the fact that both games spread simultaneously northward on the Mississippi.
The Joker came to be represented as a clown or court jester by the 1880s, due to its assumed name and also probably borrowing from The Fool in tarot cards (predecessors to the French Tarot Nouveau, which depict The Fool as a lute-playing jester, were becoming popular in Europe around the same time).