The definition of a confederate republic seems simply to be “an assemblage of societies,” or an association of two or more states into one state. The extent, modifications, and objects of the federal authority are mere matters of discretion.
So long as the separate organization of the members be not abolished; so long as it exists, by a constitutional necessity, for local purposes; though it should be in perfect subordination to the general authority of the union, it would still be, in fact and in theory, an association of states, or a confederacy.
The proposed Constitution, so far from implying an abolition of the State governments, makes them constituent parts of the national sovereignty, by allowing them a direct representation in the Senate, and leaves in their possession certain exclusive and very important portions of sovereign power.
This fully corresponds, in every rational import of the terms, with the idea of a federal government.
- from Federalist Paper #9