how does the parade celebrating southern independence day foreshadow the mingling of the north and south that occurs with rucker and miss love's pending marriage?

The celebration is bringing together two traditional "enemies". THe tradition of hatred was coming to an end. Along with telephones, automobiles and indoor plumbing, this union of North and South ushered in a new era. Similarly the union of Rucker and Miss. Love ushered in a new era of social development that broke with social traditions.