Green’s Dictionary of Slang

(US) social climbers.

1956		S. Longstreet Real Jazz Old and New 148: The uppity, the ritzy folk, don’t know the half of it [W&F].
1993		I.L. Allen City in Sl. (1995) 220: (ref. to 1880s) Social climbing: uppities (by 1880), would-be’s and [...] the Joneses.