Grave of Mary McElroy, Pres. Arthur's Substitute First Lady
Menands, New York
Chester Arthur's wife was dead before he became President, so the duties of First Lady fell to Mary Arthur McElroy, the youngest of his eight siblings. Mary was 40 years old, with a husband and kids in Albany, so as "Mistress of The White House" she entertained only during the busy winter social seasons. By all accounts she did a commendable job -- in fact, The White House during the Arthur administration was known for its gala parties.
When Mary died in 1917 she was buried in another part of the same cemetery as her famous older brother, under a simple tombstone that mentions nothing of her years in The White House.