Green’s Dictionary of Slang

to hand over, to give out.

1831		Satirist (London) 8 May 37/2: Could George so far forget himself, / In toying with his lover, / The Marchioness's love of pelf,— / And ‘Over, love; fork over’.
1835		New Yorker 2 May 3/3: After a significantly pathetic and pompous appeal in behalf of their ‘undertake-in’ the publishers close with the parting injunction—‘Reader fork over!’ [DA].
1837		Lytton Ernest Maltravers I 42: Come mem; don’t be fritted [...] where’s the money?—the old girl says you’ve got it. Fork it over.
1846		Durivage & Burnham Stray Subjects (1848) 69: So the lawyer forked over one V and kept the other.
1850		‘Ned Buntline’ G’hals of N.Y. 69: I shan’t forget it till he forks over.
1857		Bell’s Life in Victoria (Melbourne) 10 Oct. 4/2: He contractod a habit of holding on to his money, until forced by extra opportunity to fork over.
1863		T. Taylor Ticket-Of-Leave Man Act I: moss: I’ve got the flimsies — I’ll do it at seven ten. dalton: Fork over.
1884		Sporting Times 15 Nov. 5/2: ‘It was a bill for whisky and beer and cigars—’ Shifter forked over.
1889		S. Bailey Ups and Downs of a Crook’s Life 78: Now, fork over!
1897		A.H. Lewis Wolfville 37: So thar’s nothin’ for us to do but settle up an’ fork over some dust.
1903		J. Furphy Such is Life 231: Fork over that plug o’ tobacker you’re owin’ me.
1914		Ade ‘The New Fable of the Lonesome Camp’ in Ade’s Fables 261: Sometimes he would be compelled to fork over nearly half of the Gross, whereupon his Heart would ache and he would become Morose.
1924		C.E. Mulford Hopalong Cassidy Returns 169: Fork over, pronto.
1937		E. Anderson Thieves Like Us (1999) 50: I never saw a banker yet that wouldn’t fork over as soon as you throwed down on him.
1946		Mezzrow & Wolfe Really the Blues 22: This landlady would hand out a metal check and towel to the girl, while the customer forked over two bucks.
1956		S. Selvon Lonely Londoners 57: He fork over the money.
1967		Kerouac letter 21 July in Charters II (1999) 441: See if you can get those Italians and Germans and English to fork over to pay my next bills.
1973		B.S. Johnson All Bull 23: Every Sunday morning he would fork over pounds to his favourite mess waiter.
1981		H. Gould Fort Apache, The Bronx 159: Was that too much to ask when you forked over twenty-one thousand dollars.
1987		‘Joe Bob Briggs’ Joe Bob Goes to the Drive-In 36: I forked over $75 and the keys to the Dart.
1999		Guardian Guide 15–21 May 21: He’s likely to fork over a Hollywood record of some $9 million.
2003		O’Hara & Lewis Complete Idiot’s Guide to Buying and Selling a Home 35: When Do You Fork Over the Down Payment?
2010		A. Steinberg Running the Books 57: I flipped to the author’s photo [...] and forked it over.