Final answer:
John White found the letters "CRO" and the word "Croatoan" carved on a tree upon his return to Roanoke, suggesting the colonists might have moved to Croatoan Island voluntarily, as no cross symbolizing distress was found.
Step-by-step explanation:
When John White returned to Roanoke 1 1/2 years later, the letters carved on the tree were "CRO" and the word "Croatoan". The carvings were the only clues left behind after the mysterious disappearance of the colonists. It is believed that the settlers might have intermarried and joined the local Native American population, specifically the Croatoan tribe, but this theory was not given much credence by the Europeans at the time. According to the arrangements made prior to White's departure, if the colonists were forced to leave due to danger, they would carve a cross into the tree as well; no cross was found, indicating they might have relocated voluntarily to Croatoan, but White was unable to investigate further due to storms forcing his return to England.