Green’s Dictionary of Slang

(US) a derog. term for a migrant worker, orig. from Oklahoma, forced off his land during the Great Depression during the 1930s.

1919		Crowe & Chase Pat Crowe, Aviator 132: They call him ‘Oklahoma’, or ‘Oakey’ for short.
1939		J. Steinbeck Grapes of Wrath (1951) 188: Well, Okie use’ ta mean you was from Oklahoma. Now it means you’re a dirty son-of-a-bitch. Okie means you’re scum.
1943		H.A. Smith Life in a Putty Knife Factory (1948) 135: In the last few years the Okies have been moving in. They are the mountain morons from Appalachia.
1951		M. Spillane Long Wait (1954) 10: We don’t like migrants. Especially Oakies out of work.
1956		J. Patton ‘Okie’s In The Pokey’ 🎵 The sheriff caught him out with Jezabel, / Threw poor Okie in the county jail.
1969		Burns & Haggard ‘Okie from Muskogee’ 🎵 And I’m proud to be an Okie from Muskogee, A place where even squares can have a ball.
1976		N. Thornburg Cutter and Bone (2001) 249: A mean little crew-cut redneck Okie named Oral Roberts Russell.
1986		F. Taylor Auf Wiedersehen Pet Two 151: Then in unison: ‘Okie from Muskogee!’.
1999		Indep. on Sun. Rev. 12 Sept. 61: The dust-bowl, from where ‘Okies’ went to California to find work.
2000		Guardian Guide 25–31 Mar. 61: ‘No Oakies’ signs on bars and hotels.
2001		(con. 1964–8) J. Ellroy Cold Six Thousand 555: You okies, no offence, think and hate like we do.
2012		C. Merrigan ‘The Gleaner’s Union’ in ThugLit Sept./Oct. [ebook] Okies down south jumping the Dust Bowl for California.