If you are a wealthy man and found yourself in a group of wealthy men with the opportunity to found a new country, would you model that new country on a monarchy like England that imposes a hierarchy on the wealthy class or create something that looks democracy that imposes no hierarchy and leaves your wealth and your status alone?
Don’t kid yourself, class was very much a part of the founding of the United States. Washington, Jefferson and the rest did not live in shacks. The three fifths compromise, the electoral college, and the original “election/selection” of Senators are all parts of the U.S. Constitution that institutionalized class.