Before the signing of the Declaration of Independence in 1776, Adams advocated in Congress that independence was necessary to establish trade, and conversely, trade was essential for the attainment of independence; he specifically urged negotiation of a commercial treaty with France. He was then appointed, along with Franklin, Dickinson, Benjamin Harrison of Virginia and Robert Morris of Pennsylvania, "to prepare a plan of treaties to be proposed to foreign powers." While Jefferson was laboring over the Declaration of Independence, Adams worked on the Model Treaty. The Model Treaty authorized a commercial agreement with France but contained no provisions for formal recognition or military assistance. There were provisions for what constituted French territory. The treaty adhered to the provision that "free ships make free goods," allowing neutral nations to trade reciprocally while exempting an agreed-upon list of contraband. By late 1777, America's finances were in tatters, and that September a British army had defeated General Washington and captured Philadelphia. More Americans came to determine that mere commercial ties between the U.S. and France would not be enough, and that military assistance would be needed to end the war. The defeat of the British at Saratoga was expected to help induce France to agree to an alliance.