The short (approximately 200-word) declaration tied its signers into a body politic for the purpose of founding a government and swore them to comply by any rules and regulations enacted later "for the public benefit of the colony." Almost all of the adult male passengers aboard the Mayflower signed the pact (41 percent ). It was not an official document but rather a statement of principles upon which the founders agreed to base their governance. The compact itself does not specify how long it is meant to remain in effect, but early laws passed by the colonial assembly indicate that they believed it to be merely declaratory of existing rights and duties. Its importance lies in the fact that it is considered the first written constitution of what would become the United States. It can therefore be said to have begun the constitutional history of the country. Furthermore, because it is a statement of principles rather than specific rules, it allows for future amendments or new compacts to be made without changing the original declaration. The compact was written in English by John Winthrop the Younger, who was serving as governor of the Massachusetts Bay Colony at the time. He used language derived from the 1628 Charter of Charles II, which granted land claims in America by England and Ireland. This charter also served as the basis for other documents that established legal systems for those colonies and their successors.