“An Act to alter and amend an Act, intituled ‘An Act to repeal an Act intituled, An Act for making Slaves real estate,’ and the first clause of an Act intituled ‘An Act to appoint Commissioners for the purpose of obtaining an exact account of the number of the Coloured Free People and number of Negroes within this government and its dependencies, and to ameliorate the condition of the Slaves, and for other purposes’”