Paul Heinegg has documented that most of the free people of color listed in the 1790–1810 censuses in the Upper South were descended from unions and marriages during the colonial period in Virginia between white women, who were free or indentured servants, and African or African-American men, servant, slave or free. In the early colonial years, such working-class people lived and worked closely together, and slavery was not as much of a racial caste. Slave law had established that children in the colony took the status of their mothers. This meant that multi-racial children born to white women were born free. The colony required them to serve lengthy indentures if the woman was not married, but nonetheless, numerous individuals with African ancestry were born free, and formed more free families. Over the decades, many of these free people of color became leaders in the African-American community; others married increasingly into the white community. His findings have been supported by DNA studies and other contemporary researchers as well.