The lives of two sisters--Nettie, a missionary in Africa, and Celie, a southern woman married to a man she hates--are revealed in a series of letters exchanged over thirty years.

Many years ago, the color purple was available only to a privileged few because the process was very complicated and expensive. Then in 1856, a boy named William Henry Perkin was testing a hypothesis about a cure for malaria and found that his experiment resulted in something else--something vivid and rare for the times: synthetic purple. Perkin, a pioneer of the modern scientific method, made numerous advances possible, including canned food and...