The Invisible Line: Three American families and the secret journey from black to white

"The Invisible Line" by Daniel J. Sharfstein
"The Invisible Line" by Daniel J. Sharfstein
Penguin Publishing

For much of American history, racial identity has been defined in terms of black and white. But because of their heritage and physical appearance, some families walk the line between cultures.

A new book chronicles three mixed-race families whose identities were called into question at various periods in history - with surprising consequences.