Mother and Daughter characters, May and June respectively, are named after months of the year. The fact that the month of June succeeds May is fitting, as June literally succeeds May after she dies.
This movie was filmed in Columbia, Tennessee, which is the Mule Capital of the World.
"Ducktown" (noted also in the catchy song as "Ducktown USA") is where this movie fictionally 'happens' - but Ducktown is an actual town in Tennessee, located in the extreme southeast corner of the state. Johnny Knoxville is of course from nearby Knoxville, TN.
May and June stay in an apartment outside Knoxville until coming to visit Daltry. Daltry's actor, Johnny Knoxville comes from and is named after this town.