Wikipedia:
"William Jefferson Clinton was born William Jefferson Blythe III in Hope, Arkansas. His father was William Jefferson Blythe, Jr., a traveling salesman, who died in a car accident three months prior to the birth of his son.[1] Following Bill's birth, his mother, Virginia Dell Cassidy (1923-1994), traveled to New Orleans to study nursing, leaving Clinton in Hope with her parents, Eldridge and Edith Cassidy, who owned and operated a small grocery store.[11] At a time when the Southern United States was still segregated, Clinton's grandparents defied social convention and sold goods on credit to people of all races.[12] In 1950, Clinton's mother returned from nursing school and shortly thereafter married Roger Clinton, who together with his brother owned an automobile dealership in Hot Springs, Arkansas.[13] As such, Bill moved to Hot Springs in 1950 to live with his mother and stepfather.
It was not until Billy (as he was known then) turned 14 that he formally adopted his stepfather's surname of Clinton, although he had assumed use of it before then. Clinton has said that he remembers his stepfather as a gambler and an alcoholic who regularly abused his mother and, at times, his half-brother, Roger, Jr.[13][14]"