This is determined by the Constitution of the United States. That instrument provides explicitly the manner of appointing "officers of the United States." It says (Art. 2, § 2), "The President shall nominate, and by and with the advice and consent of the Senate shall appoint, ambassadors, other public ministers, and consuls, judges of the Supreme Court, _and all other officers of the United States_ whose appointments are not herein otherwise provided for, and which shall be established by law; but the Congress may by law vest the appointment of such _inferior officers_ as they think proper in the President alone, in the courts of law, or in the in the heads of departments." In the next clause it declares, that "the President shall have power to fill up all vacancies that may happen during the recess of the Senate, _by granting commissions_ which shall expire at the end of their next session." From these clauses it appears that all "officers of the United States" are nominated, and by and with the advice and consent of the Senate are appointed, by the President; and it is inferred that they are "commissioned" by the President. Now two questions arise: whether an officer in the "army" of the United States is an "officer of the United States" in the sense of the Constitution, and whether he is an "inferior officer." He is not an "inferior officer" in the sense of the Constitution; for his appointment has never been vested "in the President alone, in the courts of law, or in the heads of departments." He is an "officer of the United States." In support of this is universal custom, which has always treated him as such, the express action of President Monroe and Congress in 1821 with regard to the office of Adjutant-General (3 Story, Com. on Const. § 1531, note), and sundry precedents. I conclude, therefore, that Edward Webster, assuming to be an "officer of the United States," but not having been "nominated by the President, and by and with the advice and consent of the Senate appointed," nor being "commissioned" by the President, is not constitutionally an officer of the "army" of the United States, nor entitled to detain the petitioner. He is commissioned by the Governor of Massachusetts, who cannot give any power in the "army" of the United States. The question next arises, whether any person is authorized to detain the petitioner. Webster is not. Who is?