Article II, Section 2, Clause 1:
The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Offices, and he shall have Power to grant Reprieves and Pardons for Offences against the United States, except in Cases of Impeachment.
Surprisingly little discussion of the Commander-in-Chief Clause is found in the Convention or in the ratifying debates. From the evidence available, it appears that the Framers vested the duty in the President because experience in the Continental Congress had disclosed the inexpediency of vesting command in a group and because the lesson of English history was that danger lurked in vesting command in a person separate from the responsible political leaders. 1 But the principal concern here is the nature of the power granted by the clause.