Historical clue formulations

• 43rd prez — 2021-03-31
• Potus #43 — 2018-11-14
• Prez with the same initials as an N.Y.C. landmark — 2017-11-14
• Early 2000s White House inits. — 2016-09-06
• Monogram of the author of "A Charge to Keep: My Journey to the White House" — 2013-08-02