Green’s Dictionary of Slang

(US; later US black) a rich person; in pl., the social élite.

1865		H.L. Williams Joaquin 156: The ‘hard-fists’ and the ‘silk-stockings,’ few, however, began to cover the blank of a petition with signatures.
1896		F. Hutcheson Barkeep Stories 57: ‘[S]ome o’ dem’s kinder givin’ me de laugh on ’count o’ me talk not bein’ so swell as some o’ dem silk stockin’s use’.
1914		Cyclopedia of Amer. Government III 309/1: Silk Stockings, a derisive appellation bestowed by the ‘practical politicians’ upon those citizens of wealth and high social position who occasionally interfere in politics in support of some reform measure or candidate [DA].
1915		E. Poole Harbor (1919) 221: I saw one who can have my vote – Believe me, some silk stockings!
1920		Ade Hand-made Fables 93: He never goes near a Silk Stocking unless he wants to use him, and then he sends for him.
c.1926		in P. Smith Letter from My Father (1978) 169: Boos, catcalls and charges of ‘silk stocking,’ ‘high hat’.
1935		A.J. Pollock Und. Speaks n.p.: Silk hat, a wealthy business man who likes to gamble and enjoys frolicking around.
1983		R. Klein Jailhouse Jargon and Street Sl. [unpub. ms.].