During and after the war, Jenifer became increasingly concerned about national affairs. He represented his state in the Continental Congress (1778–82) while simultaneously serving as president of Maryland's first senate (1777–80). As manager of his state's finances between 1782 and 1785, Jenifer drew on his experiences as a landholder to help the state survive the critical postwar economic depression. Along with James Madison, John Dickinson, George Mason and his good friend George Washington, Jenifer began to explore ways to solve the economic and political problems that had arisen under the weak Articles of Confederation. Consequently, he attended the Mount Vernon Conference, a meeting that would lead eventually to the Constitutional Convention.