Adialogue between andrew jackson and fredrick douglass

  This is a toughie. 
Where the two would disagree: Clay was a whig, a sort of father figure to whigs and even Republicans like A. Lincoln. (Once the Repub party was formed, abt 1856, it included many Whigs) Generally whigs believed in expansion of fed power to include projects such as canals and road building; in other words, infrastructure. Democrats like Jackson were opposed to Fed power. jackson didn't even believe the Fed gov had a right to build state roads. And he was adamantly opposed to the Fed Bank. 

However, both were pro Union and worked to defeat state rights and even secession when it threatened. Jackson opposed South Carolina and its efforts at nullification. And Clay was known as the Great Compromiser, instrumental in keeping the South from seceeding. The Compromise of 1850 was one of his main triumphs: this at least put off the Civil War for a decade. So both AJ and HC were Southerners who were pro union. 

Thus you'd want to made their dialog include where they agreed and disagreed.