The United States

is an officer appointed by the president. He must be learned in the law, and be sworn or affirmed to a faithful execution of his office. His duties are ta prosecute and conduct all suits in the Supreme Court, in which the United States shall be concerned, and give his advice upon questions of law, when required by the president, or when requested by the heads of any of the departments, touching matters that may concern their departments; Act of 24 Sept. 1789; salary is three thousand five hundred dollars per annum, and he is allowed one clerk, whose compensation shall not exceed one thousand per annum; Act 20 Feb. 1819, 3 Story’s Laws, 1720, and Act 20 April, 1818, s. 6, 3 Story’s Laws, 1693.