Manteo White left his family in Roanoke for over 2 years, he originally only left to get some supplies for his new born child. Though, when he was ready to set sail to finally see his family after 1 month. A war started, making him push back the date. When returning, he was left to find little clues no one to this day can piece together.
Over the many years since this strange occurance, many people have came up with their own ideas of what happened. Ranging from natural disaster to turning into animals with spells. This is still a great mystery.
What I believe happened was that after months of no returning supplies, and stress of survival started to set in. The Colonists took matters into their own hands. By marrying into the tribe, they were left with a sense of security and had a greater chance of survival. This theory could help prove how natives have blue eyes, and "white skin". Overall all these theories have their down falls, but no one can ever quite figure out what happened so its pretty much pick and choose to believe what you want.