His mother, Charity, escaped twice from Maryland. The first time, she and four children were all recaptured and returned to slavery. A few months later, Charity escaped again, taking only her two younger daughters with her, and reached her husband in New Jersey. Following her escape, Charity and Levin had 14 more children, of whom William was the youngest. Though these children were born in the free state of New Jersey, under Maryland and federal slave law, they were still legally slaves, as their mother was an escaped slave. According to New Jersey law, however, they were free.