On September 17, 1787, six years after fighting stopped in the war for independence, delegates to the Constitutional Convention in Philadelphia signed the document that has endured as the most influential exemplar in the world of government by and for the people.

The U.S. Constitution is an extraordinary document. A new book by the historian and journalist Jill Lepore is an insightful, sweeping masterpiece following the twists and turns of the Constitution's life.

We the People: A History of the U.S. Constitution reveals how central the amendment process is to the founding document, and makes the case that decades of political gridlock, and a lack of amendments, is part of the problem we face today.

Jill Lepore is a professor of American history at Harvard University. She also teaches law at Harvard law school, and she is a staff writer for the New Yorker, and the author of more than a dozen books.