Which 1781 document declared that "each state retains its sovereignty, freedom and independence"?

The "shot heard round the world" was fired in 1775 at the battle of which Massachusetts town? In 1776, Adam Weishaupt founded which Bavarian secret society of Enlightenment thinkers? The Broadway musical "1776" climaxes with which historic event? In 1776, George Washington and his troops crossed which river to attack the Hessians? In which 1783 treaty did "His Britannic Majesty" acknowledge the United States to be "free, sovereign and independent"? Which 1783 treaty, negotiated by John Adams, Benjamin Franklin and John Jay, ended the Revolutionary War? At 81, which man was the oldest delegate at the 1787 Constitutional Convention? Which 1787 law governing the area north of the Ohio River became a model for territories entering the Union?