CHICAGO—The proud and ancient Cherokee Nation was thrust into the spotlight during a taping of The Oprah Winfrey Show this week, taking center stage as one-eighth of actress Cameron Diaz's ancestry. "How exotic," Ms. Winfrey commented on the What Happens In Vegas costar's heritage, briefly calling attention to the Cherokee people and their millennia of vibrant culture and tradition. "Tell us what it's like working with Mike Myers." The instance marked the highest-profile mention of the tribe since 1838, when thousands of Cherokee men, women, and children were forcibly rounded up and marched 1,000 miles to what is now known as Oklahoma.