Green’s Dictionary of Slang

1. (orig. US) a spree, a noisy revel.

1868		N.Y. Herald 10 July 8/3: The Seventh regiment has gone on a jamboree to Norwich, Connecticut [DA].
1881		NY Tribune 2 July 6/1: ‘Did Conkling make the jamboree? / What could his reason be?’ / ‘Why, that I cannot tell,’ qoth he, / ‘But t’was a famous jamboree!’ .
1890		Sporting Times 4 Jan. 2: One day a friend and myself rode into town when old P—— was on the ‘jamboree’.
1902		E. Dyson ‘The Big “Bust”’ in Bulletin Reciter 1880–1901 144: There he held his jamboree for fourteen days, I swear.
1903		A. Binstead Pitcher in Paradise 66: Occasional indulgence in the jamboree is not a good thing for a fashionable light-weight jockey.
1912		Ade Knocking the Neighbors 51: I grabbed you because I knew you had been to all the Places that keep Open and could frame up a new Jamboree every day.
1925		Wodehouse Carry on, Jeeves 70: I had met Bicky for the first time at a species of beano or jamboree.
1936		(con. 1830s–60s) ‘Miles Franklin’ All That Swagger 299: Syme and Jimmy were lucky young devils because this detachment [...] would go right on to England for a jamboree.
1947		Christian Science Monitor 1 Mar. 10/4: The club will make its presentation at its football jamboree at the close of each grid season [DA].
1981		W. Boyd Good Man in Africa 81: ‘The next big jamboree we have here, let’s invite all the local political people’.

2. (US) a disturbance or fight.

1872		Schele De Vere Americanisms 611: Jamboree, a row, a disturbance.
1877		E.L. Wheeler Deadwood Dick in Beadle’s Half Dime Library I:180/1: I’ll take you over to my coop, and you can lay low there until this jamboree blows over.
1907		C.E. Mulford Bar-20 xxv: Tell us about that jamboree over in th’ Panhandle.
1922		P.A. Rollins Cowboy 77: ‘Jamboree’ might indicate, among other things, an innocent dancing party, a drunken debauch, or an active event, whether the last were a pistol fight or a stampede of animals.
1978		H.R. Haldeman Ends of Power 11: If brother Colson is involved in this little jamboree [i.e. the Watergate break-in], we’re in for a lot of problems.
1990		(con. early 1950s) J. Ellroy L.A. Confidential 28: Stens going crazy, booze, a jamboree – bash the cop bashers.