Months after the Battle of Yorktown, Morris issued the "Report on Public Credit," an ambitious economic plan calling for the full payment of the country's war debt through new revenue measures. It included a head tax on slaves in the various states, but above all, he pushed for a federal tariff of five percent on all imported goods, which would require an amendment to the recently approved Articles of Confederation. Such an amendment would greatly strengthen the power of the national government, but the amendment process required the consent of each state, and many states were reluctant to alter the balance of power between the states and the national government. The Articles gave Congress the sole power to conduct foreign policy, but the states retained all power over funding; Congress had no independent power to raise funds, and lacked any mechanism to force states provide the funds that they owed to Congress. Writing to the state governors, Morris argued that it was "high time to reliever ourselves from the infamy we have already sustained, and to rescue and restore the national credit. This can only be done by solid revenue." By late 1782, all of the states but Rhode Island had agreed to back an amendment allowing the tariff, but that was enough to block the amendment.