Mary Elizabeth Bowser (born c. 1840) was a freed slave who worked as a Union spy for Ulysses S. Grant during the Civil War. She operated as a servant in Richmond, Virginia in the home of Confederate President, Jefferson Davis where she gathered important military information to pass on to the Grant administration.

A female spy ring was organized by Elizabeth Van Lew who helped get Mary Bowser placed as close to the tactical planning of Confederate South as she could. Because of racial prejudice at the time, it was assumed that black people were illiterate and unintelligent. Davis and his staff knew they had an information leak, but they couldn’t figure out who the spy was. Little did they know, a Union spy found her way into the hive of the Confederate White House as part of an abolitionist woman’s spy ring. Bowser was well educated, and some sources claim that she had a photographic memory. She was able to gather considerable military intelligence by simply doing her job. They never suspected Bowser. Their underestimation of Bowser as an African-American and a woman may have cost them the war. 

In 1995, Mary Bowser was inducted into the U.S. Army Military Intelligence Corps Hall of Fame as “one of the highest placed and most productive espionage agents of the Civil War.”