The modern usage of the term president to designate a single person who is the head of state of a republic can be traced directly to the United States Constitution of 1787, which created the office of President of the United States. Previous American governments had included "presidents" (such as the president of the Continental Congress or the president of the Massachusetts Provincial Congress), but these were presiding officers in the older sense, with no executive authority. It has been suggested that the executive use of the term was borrowed from early American colleges and universities, which were usually headed by a president. British universities were headed by an official called the "Chancellor" (typically a ceremonial position) while the chief administrator held the title of "Vice-Chancellor". But America's first institutions of higher learning (such as Harvard University and Yale University) didn't resemble a full-sized university so much as one of its constituent colleges. A number of colleges at Cambridge University featured an official called the "president". The head, for instance, of Magdalene College, Cambridge was called the master and his second the president. The first president of Harvard, Henry Dunster, had been educated at Magdalene. Some have speculated that he borrowed the term out of a sense of humility, considering himself only a temporary place-holder. The presiding official of Yale College, originally a "rector" (after the usage of continental European universities), became "president" in 1745.
The President of the United States ( POTUS ) [B] is the head of state and head of government of the United States of America . The president directs the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces .