Many countries have borrowed from it, none have improved upon it. Strong as it is, it's only as strong as the Supreme Court Justices charged with following and interpreting it, and only as strong as the Citizens of the US are willing to allow it to be. Hopefully the next 235 years will see it remain as strong, if not stronger, as it is now.
National Constitution Center
Field Trip: The National Constitution Center, Philadelphia, PA
The history of our Constitution is inexorably linked to the history of our country itself. Just about every important moment in U.S. history therefore receives some coverage at the Center, from the American Revolution, to the Civil War, to Watergate.