Why was the federal government granted the ability to maintain an army during peacetime by the constitution?

The clauses of the Constitution, which give Congress authority to raise and support armies, and so forth, were not inserted to endow the national government rather than the States with the power to do these things but to designate the department of the Federal Government, which would exercise the powers. As we have noted above, the English king was endowed with the power not only to initiate war but the power to raise and maintain armies and navies.1637 Aware historically that these powers had been used to the detriment of the liberties and well-being of Englishmen and aware that in the English Declaration of Rights of 1688 it was insisted that standing armies could not be maintained without the consent of Parliament, the Framers vested these basic powers in Congress.

Explanation:

do you have a list of sources to choose from?