In order order for this Congress to pass a measure under the Articles of Confederation, there had to be unanimous approval between the states, since the Founders were very paranoid about centralized power.
The answer to your question would be property.
C. winning the free exercise of voting rights
...he believed in the limited use of federal power but also that states were not truly sovereign.
He vetoed it for various reasons. For starters, he believed that it was a thing up to individual states and that it infringed on the states right to choose. Another reason was that he believed that such beneficial extension would not make people equal, but rather it would be racist towards the white people. His main argument, however, was that the bill would have a certain group gain rights that they are not entitled to, while a large part of the states does not even have representation in the congress, and that the congress needs to be enlarged first.
