Entry in progress—B.P.
 
[This entry was assisted by research from Fred Shapiro of the American Dialect Society.]
 
Wikipedia: Poker
Poker is a family of gambling card games involving betting and individual play, whereby the winner is determined by the ranks and combinations of players’ cards, some of which remain hidden until the end of the game. Poker games vary in the number of cards dealt, the number of shared or “community” cards, and the number of cards that remain hidden. Betting procedures vary widely among dozens of different poker game variants.
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History
English actor Joseph Cowell reported in his memoirs that the game was played in New Orleans, Louisiana in 1829, with a deck of 20 cards, and four players betting on which player’s hand was the most valuable. Jonathan H. Green’s book, An Exposure of the Arts and Miseries of Gambling (G. B. Zieber, Philadelphia, 1843), described the spread of the game from there to the rest of the country by Mississippi riverboats, on which gambling was a common pastime. As it spread north along the Mississippi River and to the West during the gold rush, it is thought to have become a part of the frontier pioneer ethos.
 
Soon after this spread, the full 52-card French deck was used and the flush was introduced. The draw was added prior to 1850 (when it was first mentioned in print in a handbook of games). During the American Civil War, many additions were made including stud poker (specifically five-card stud) and the straight. Further American developments followed, such as the wild card (around 1875), lowball and split-pot poker (around 1900), and community card poker games (around 1925).
 
(Oxford English Dictionary)
poker, n.
Etymology:  Probably < French poque, a similar bluffing card game (1752) or its etymon poquer to place a stake in this game (1752) < German pochen (1741 or earlier in this sense; > Pochen , the name of the game (1741 or earlier), also Poch (a1865), Pochspiel (a1811 or earlier)), spec. use of pochen to boast, brag (now rare in this sense), to insist, lit. ‘to knock, rap’ (Middle High German puchen , bochen ), ultimately of imitative origin. Compare earlier brag n.1 6.
The origin of the final -er in uncertain; it might be < the ending of the French verb

poquer, or it might represent a disyllabic pronunciation of French poque. Compare also German Pocher one of the pools in the board accompanying the German game, where stakes are placed (undated).
In form with -ch- probably after German.
The English word was reborrowed into French in the form pocker (1855, now poker).
 
orig. U.S.
A card game related to brag, played by two or more people who bet on the value of the hands dealt to them, one of whom wins the pool either by having the highest scoring combination of cards at the showdown, or by forcing all opponents to concede without a showing of the hand, sometimes by means of a bluff. Also fig.
1832   Globe (Washington, D.C.) 3 Sept. 2/5   Who is notorious for his skill and dexterity at Lieu, poker and Kentucky Brag? ... Centre County (Pa.) Democrat.
1836   J. Hildreth Dragoon Campaigns Rocky Mts. xv. 128   The M—lost some cool hundreds last night at poker.
 
16 January 1830, Georgian (Savannah, GA), “Laws of Georgia,” pg. 2, col. 5:
... at any game of Faro, Loo, brag, Bluff, or any other game played with cards, ...
 
3 September 1832, The Globe (Washington, DC), pg. 2, col. 5:
Who is notorious for his skill and dexterity at Lieu, poker and Kentucky Brag? (...) Centre County (Pa.) Democrat.
 
8 July 1835, Commercial Bulletin and Missouri Literary Register (St. Louis, MO), “Literary,” pg. 2, col. 1:
Some scores of “sportsmen,” each a mighty dab in
“Brag,’ “Poker,” “Eucre,”—friendly in the main—
 
29 January 1836, New-Orleans (LA) Commercial Bulletin, pg.?, col. 5:
PLAYING CARDS—Ehrle (?—ed.), Merry Andrew Highlander, Poker and Kupfer
Kaftern cards for sale by
B H SIMMONS & CO., 79 Chartres street
 
25 January 1837, The Picayune (New Orleans, LA), pg. 4, col. 1:
B. H. SIMMONS & CO. are now receiving eagle, highlander, poker, merry andrew, French and German playing cards; ...
 
Chronicling America
25 February 1837, True American (New Orleans, LA), pg. 4, col. 4:
B. H. SIMMONS & CO, are now receiving from on board ship Orleans, Eagle, Highlander, Poker, Merry Andrew, French and German playing cards; ...