Which 20th century U.S. president was the father of an illegitimate child named Elizabeth Ann?

Nanna Popham "Nan" Britton (November 9, 1896 – March 21, 1991) was the mistress of Warren G. Harding, the 29th President of the United States. In 1928, Britton revealed that her daughter, Elizabeth Ann Britton Harding Blaesing, had been fathered by Harding while he was serving in the United States Senate, a year before he was elected to the presidency. Her revelation was controversial during her lifetime, but was confirmed by DNA testing in 2015.

Nan Britton, who made her claim public with the publication of her book, The President's Daughter (Elizabeth Ann Guild, 1928), could never produce primary source evidence to prove that Harding was the father of Elizabeth Ann. As a child and young adult, Elizabeth Ann used Harding's surname. However, due to a doctor's error, the name of Emma Eloise Britton was written on her birth certificate. Ultimately, she lived for 86 years (October 22, 1919 – November 17, 2005), and she died in the state of Oregon.