Green’s Dictionary of Slang

(US) money.

1865		L.N. Boudrye Fifth N.Y. Cavalry 195: The paymaster [...] is relieving himself freely of ‘stamps,’ as the boys call his greenbacks [DA].
1874		Cultivator and Country Gentleman (US) 10 Dec. 799/1: We allow ourselves to say of a rich man that he has got ‘stamps’.
1882		J.D. McCabe N.Y. 161: If I had his stamps I wouldn’t hang around nights to catch a five-cent fare [DA].
1890		‘’Arry on the ’Oliday Season’ in Punch 16 Aug. 74/3: Though travelling’s cheap, / It do scatter the stamps jest a few, if you don’t care to go on the creep.
1893		L. Chittenden ‘A Stockman’s Adventures in New York’ in Ranch Verses 156: I hed heerd thet New York city wuz a dandy place fer camps, / With water, grass, ’n clover – (pervided yer hed stamps).
1905		Sporting Times 4 Mar. 2/3: Remanded till nex’ Monday, an’ none of us got the stamps to buy the bloke off with.
1927		C. Samolar ‘Argot of the Vagabond’ in AS II:9 385: Stamps was at one time a name for money.
1996		Eble Campus Sl. Sept. 6: stamp – dollar.
2016		Jeezy ‘Recipe’ 🎵 If we talkin’ ’bout them stamps, you know who be the champ / Tryna get that extra money.