The Mayflower Compact was the first governing document of the Plymouth Colony. IT was written by the pilgrims prior to landing at Plymouth after the trip across the Atlantic.
The documents was signed when the Hudson River bound pilgrim accidently ended up in Massachusetts. Some of the non-religious settlers claimed that because they were not in New York as planned, the agreements they had made regarding government and labor where now null and void. They claimed that a virtual anarchy was now in effect, and that nobody had the power to command anyone.
To solve this dilemma, all the male passengers on the Mayflower signed the Mayflower Compact, which established a basic government and procedural rules for the colony. It was in essence a social contract where everyone agreed to follow certain rules for the sake of survival.
Some historian point to this as the beginning of a democratic tradition in the U.S., but the significance of the document may be overstated.