The prize for the earliest picture goes to Benjamin West's "The Golden Age" (1776), a sentimental portrait of a mother and her sleeping child.

WSJ: Fifty Has Seldom Looked So Good Bared | The Naked Museum | Sheldon Museum of Art | By Willard Spiegelman

Her mother, the painter Elaine Fasula, did a beautiful portrait of her, and I've placed it above the stairway to the basement.

WSJ: Philippe Petit on the House That Came Wired