Mary Bowser and Elizabeth “Bet” Van Lew were real people who spied on behalf of the Union. About one-third of white Virginians believed their state should remain in the Union rather than seceding, although few of them went as far as Bet did to thwart the Confederate cause. Ulysses S. Grant later wrote to Bet: “You have sent me the most valuable information received from Richmond during the war.” Mary Bowser was at the heart of that information gathering. In her Civil War diary, Bet wrote, “When I open my eyes in the morning, I say to the servant, ‘What news, Mary?’ and my caterer never fails!” (caterer originally meant "one who serves the household," a forerunner to the modern meaning of one who provides fine fare at a catered reception).
Very little specific information is known about Mary Bowser. She was baptized at St. John’s Episcopal Church in Richmond on May 17, 1846, and married there on April 16, 1861. It was extremely unusual for black people to be baptized or married in this church, which served Richmond's elite white community, indicating that the Van Lews treated her differently from other slaves or free black servants. Historical accounts indicate that Mary was educated either in Philadelphia, Pennsylvania or in Princeton, New Jersey. Few other details about her can be proven.
Read my latest research on the real Mary Bowser in Encyclopedia Virginia (Warning for lovers of the novel: you'll learn that the real Mary's life was not the same as what's in the novel, for reasons I discuss below)
My first article about Mary Bowser's life, "The Black Slave in the Confederate White House," can be read in the New York Times. You'll see that two more years of research have revealed a lot more than we knew when I wrote this in 2012.