John Adams assisted in drafting a document.
John Adams . He assisted Thomas Jefferson in drafting the Declaration of Independence in 1776 , and was its foremost advocate in the Congress . Adams was the primary author of the Massachusetts Constitution in 1780 which influenced American political theory , as did his earlier Thoughts on Government ( 1776 ) . The Declaration of Independence is the statement adopted by the Second Continental Congress meeting at the Pennsylvania State House ( Independence Hall ) in Philadelphia on July 4 , 1776 , which announced that the thirteen American colonies , then at war with the Kingdom of Great Britain , regarded themselves as thirteen newly independent sovereign states , and no longer under British rule . John Adams persuaded the committee to select Thomas Jefferson to compose the original draft of the document , which Congress would edit to produce the final version . The United States Declaration of Independence inspired many other similar documents in other countries , with its ideas gaining adherence in the Low Countries , as well as in the Caribbean , Spanish America , the Balkans , West Africa , and Central Europe in the decades up to 1848 .