Euchre is a trick-taking card game most commonly played with four people in two partnerships with a deck of 24 standard playing cards. It is the game responsible for introducing the Joker card into modern packs; this was invented around 1860 to act as a top trump or best bower . It is believed to be closely related to the French game Écarté that was popularized in the United States by the Pennsylvania Dutch, and to the seventeenth-century game of bad repute Loo. It may be sometimes referred as "Knock Euchre" to distinguish it from Bid Euchre.
Euchre appears to have been introduced into the United States by the early German settlers of the State of Pennsylvania, and from that state gradually to have been disseminated throughout the nation. It has been more recently theorized that the game and its name derive from an eighteenth-century Alsatian card game named Juckerspiel, a derivative of Triomphe.
No mention of Euchre is made in the curious and elaborate treatise by Samuel Weller Singer, entitled Researches into the History of Playing Cards, 4to., London, 1816; nor in any of the English editions of Hoyle's Games; nor in Captain Crawley's Handy Book of Games for Gentlemen, 12mo., London, 1860. No notice of the game is to be found in the long and learned array of articles on the various games of cards in the Album des Jeux, 12mo., Paris, 1847, a careful collection of modern games of cards by M. Van-Tenac, and its name is legion in the extended Dictionnaire des Jeux of the Encyclopedic Methodique.
Wikipedia, Euchre, http://en.wikipedia.org/wiki/Euchre (as of Apr 1, 2010)