<P> The Framers of the U.S. Constitution understood the role of high officers specially imbued with certain authority to act on behalf of the head of state within the context of their earlier experience with the British Crown . Day - to - day administration of the British Government was based on persons "holding sovereign authority delegated from the King that enabled them in conducting the affairs of government to affect the people ." This was an extension of the general common - law rule that "where one man hath to do with another's affairs against his will, and without his leave, that this is an office, and he who is in it, is an officer ." </P> <P> According to an April 2007 memorandum opinion by the United States Department of Justice's Office of Legal Counsel, addressed to the general counsels of the executive branch, defined "officer of the United States" as: </P> <P> a position to which is delegated by legal authority a portion of the sovereign power of the federal government and that is' continuing' in a federal office subject to the Constitution's Appointment Clause . A person who would hold such a position must be properly made an' officer of the United States' by being appointed pursuant to the procedures specified in the Appointments Clause . </P> <P> The difference between an "Officer of the United States" and a mere "Employee of the United States," therefore, ultimately rests on whether the office held has been explicitly delegated part of the "sovereign power of the United States". Delegation of "sovereign power" means possession of the authority to commit the federal government of the United States to some legal obligation, such as by signing a contract, executing a treaty, interpreting a law, or issuing military orders . A federal judge, for instance, has been delegated part of the "sovereign power" of the United States to exercise; while a letter carrier for the United States Postal Service has not . Some very prominent title - holders, including the White House Chief of Staff, the White House Press Secretary and most other high - profile presidential staff assistants, are only employees of the United States as they have no authority to exercise the sovereign power of the federal government . </P>

Who commissions all the officers in the united states military