In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Why might a mixed race native American need to be officially adopted?, Context: The social identity of the children was strongly determined by the tribe's kinship system. Among the matrilineal tribes of the Southeast, the mixed-race children generally were accepted as and identified as Indian, as they gained their social status from their mother's clans and tribes, and often grew up with their mothers and their male relatives. By contrast, among the patrilineal Omaha, for example, the child of a white man and Omaha woman was considered "white"; such mixed-race children and their mothers would be protected, but the children could formally belong to the tribe as members only if adopted by a man.
the child of a white man and Omaha woman was considered "white"