Many Europeans who arrived in North America during the 17th and 18th centuries came under contract as indentured servants. The change from indentured servitude to slavery was a gradual process in Virginia. The earliest legal documentation of such a shift was in 1640. This is where an African, John Punch, was sentenced to lifetime slavery for attempting to run away. This case also marked the disparate treatment of Africans as held by the Virginia County Court, where two white runaways received far lesser sentences. After 1640, planters started to ignore the expiration of indentured contracts. They kept their servants as slaves for life. This was demonstrated by the case Johnson v. Parker. The court ruled that John Casor, an indentured servant, be returned to Johnson who claimed that Casor belonged to him for his life. According to the 1860 U. S. census, 393,975 individuals, representing 8% of all US families, owned 3,950,528 slaves. One-third of Southern families owned slaves. Slavery in United States was legally abolished by Thirteenth Amendment to the United States Constitution in 1865.