According to the Okie From Muskogee Songfacts, Haggard and his band started writing this when their tour bus passed through Muskogee, Oklahoma. It started out as a joke making fun of small town rural folks.
We don't smoke marijuana in Muskogee
We don't take our trips on LSD
We don't burn our draft cards down on Main Street
We like livin' right, and bein' free