How has the amendment process make the constitution a flexible and enduring document?

The amendment process allows the Constitution to be amended through the passing of time. There are two ways to amend the Constitution either the proposal for amendment must be approved by 2/3 of the House of Reps. and Senate or 2/3 of states can approve it at a National Constitutional Convention. Once approved, it is then ratified by 3/4 of the state legislatures or 3/4 of state held conventions. 

The second , larger puritan colony of massachusetts bay was conceived as a "city upon a hill". but it also struggled with internal turmoil like the salem witch trials and external conflicts like king philip's (metacom's) war.