George Washington's name is inseparable from America, and not only from the nation's history. It identifies countless streets, buildings, mountains, bridges, monuments, cities and people.

In a puzzling twist, most of these people are black. The 2000 U.S. census counted 163,036 people with the surname Washington. Ninety percent of them were African American, a far higher black percentage than for any other common surname.

Some historians theorize that large numbers of blacks chose the name Washington in the process of asserting their freedom after the Civil War....