Salutation of a social letter: My dear Mr. President.
Conclusion: I have the honor to remain most respectfully [or sincerely] yours.
Inscription on envelope: President Woodrow Wilson.
To the Vice-President, an official letter begins, Sir, or Dear Sir.
Conclusion: I have, Sir, the honor to remain your most obedient servant.
Salutation of a social letter: My Dear Mr. Marshall.
Conclusion: as given for president.
Inscription on envelope: The Vice-President, Thomas R. Marshall.
To a Justice of the Supreme Court, an official letter begins and concludes as in the case of a vice-president.
Salutation of a social letter: Dear Mr. Justice White, or Dear Justice White.