Clearly, the founders who realized the value of Confucian personal virtual cultivation, adopted his individual moral improvement in their efforts to reconstruct a new virtue for the new nation. That explains why the founders promoted the Confucian moral philosophy in the founding era. As for how they used Confucian moral philosophy, please read Confucius in the American Founding.
One of the legacies from the founding fathers efforts is that their efforts had produced the phenomenon as discovered by Alexis de Tocqueville in 1803 "that Americans were very good at associating with one another and subordinating their individualism to voluntary groups of one type or another."(Francis Fukuyama, Confucianism and Democracy).