Theconstitution was and is imperfect. It took a civil war to establish that the principles enumerated in its Bill of Rights extended to all Americans, and the struggle to live up to those principles continues today. But focusing on the Constitution’s flaws can overshadow what it did achieve. Its revolutionary ambition was to forge, out of a diverse population, a new national identity, uniting Americans under a banner of ideas. To a remarkable extent, it succeeded.