=Division of Powers.=--The Federal Constitution has marked out a definite sphere of power for the states, on the one hand, and another sphere for the national government on the other, and each within its sphere is supreme. Upon the domain thus created for each the other may not encroach. Each is kept strictly within its own constitutional sphere by the federal Supreme Court, and the balance between the union and its members is harmoniously preserved. The states were already in existence with organized governments in operation when the national government was created. The founders of the national government conferred upon it only such powers as experience and reason demonstrated could be more effectively regulated by a common government than by a number of separate governments; they left the states largely as they were, and limited their powers only so far as was necessary to establish a more effective union than the one then existing. Experience had taught them, for example, that commerce with foreign countries and among the states themselves should be regulated by a single authority acting for the entire country: only in this way could uniformity be secured, and uniformity in such matters was indispensable to the peace and perpetuity of the union. Accordingly, the national government was vested with power over this and other matters which clearly required uniformity of regulation, and the remaining powers of government were left with the states, where they had always been. Thus it came about that the national government was made an authority of enumerated or delegated powers, while the states have reserved powers. _Prohibitions._--It was thought wise, however, to prohibit both the national government and those of the states from doing certain things, and thus we find provisions in the Federal Constitution forbidding both governments from granting titles of nobility, from passing ex post facto laws, bills of attainder, etc. Likewise the states were prohibited from entering into treaties with foreign countries, from coining money, from impairing the obligation of contracts, and from passing laws on certain other subjects which it was clearly unwise to leave to state regulation.