The Answer:

The much talked about "W." stands for Walker. The name comes from his grandmother, Dorothy Walker, who married Prescott Sheldon Bush on Aug. 6, 1921. One of their five children was the country's 41st president (and George W. Bush's father) George Herbert Walker Bush.

Incidentally, Dorothy Walker's father, George Herbert Walker, established the Walker Cup in 1922. The Walker Cup is a golf tournament held every two years that features the best amateurs from Great Britain, Ireland, and the United States.

—The Fact Monster