Yet for centuries, Virginia law defined race in just a handful of categories - white, black, free people of color, Indian... In the most egregious example of racial stereotyping, Dr. Plecker sought to define "pure" whites. By his standards, codified by the General Assembly in the 1924 Racial Integrity Act, one drop of Negro blood would cause a person to be categorized as black. That was designed to stop light-skinned people with black ansestry from "passing" as white people and thus avoiding the Jim Crow discrimination laws.
Dr. Plecker sought to categorize many of the "Indians" in Virginia as black. He was forced to finesse the equivalent of one drop of Indian blood, however. Many of the so-called "First Families of Virginia" traced their ancestry back to the son of Pocahontas and John Rolfe, and were proud of their connection to what they considered to be Native American royalty.
As described in Recollections Grave and Gay by Mrs. Burton Harrison (1843-1920):
As a result, Virginians whose ancestry was one-sixteenth Native American or less were declared to be "white" in the Racial Integrity Law of 1924. Whites could not have one drop of black blood, but they could have a Native American grandparent.