McCormick said that Tyler "conducted his administration with considerable dignity and effectiveness."[182]

Tyler on a U.S. postage stamp, Issue of 1938
Tyler's assumption of complete presidential powers "set a hugely important precedent", according to a biographical sketch by the University of Virginia's Miller Center of Public Affairs.[1] Tyler's successful insistence that he was president, and not a caretaker or acting president, was a model for the succession of seven other vice presidents (Fillmore, Andrew Johnson, Arthur, Roosevelt, Coolidge, Truman, and Lyndon B. Johnson) to the presidency over the 19th and 20th centuries upon the death of the president. The propriety of Tyler's action in assuming both the title of the presidency and its full powers was legally affirmed in 1967, when it was codified in the Twenty-fifth Amendment to the United States Constitution.[183]
Some scholars in recent years have praised Tyler's foreign policy. Monroe credits him with "achievements like the Webster–Ashburton treaty which heralded the prospect of improved relations with Great Britain, and the annexation of Texas, which added millions of acres to the national domain". 