Which document was signed in 1620 to give a voice to everyone in the colony?

The Mayflower Compact is the document that was signed in 1620 by the Pilgrims aboard the Mayflower. It established a form of self-governance for the new colony at Plymouth and is regarded as one of the first attempts at democracy in the New World. The Compact was significant because it outlined how the settlers would create a government and abide by its rules, emphasizing the notion of collective decision-making and mutual consent among the colonists. This was an essential step towards the concept of a government that derives its authority from the people, which is a fundamental principle in the development of American democracy.

The other options, while historically significant, do not relate to the establishment of self-governance in the same way. The Declaration of Independence was signed in 1776 to proclaim independence from British rule, the Magna Carta was signed in 1215 in England and primarily limited the powers of the monarchy without giving a direct voice to the colonies, and the Federalist Papers were a series of essays published in the late 18th century advocating for the ratification of the U.S. Constitution, which came much later than 1620.