When did "The Oprah Winfrey Show" become nationally popular?

Oprah Winfrey is not only famous but powerful in the entertainment industry. Her TV talk show was first seen locally in Chicago in 1984. "The Oprah Winfrey Show" went national two years later and became a huge hit.
    She has announced plans to end the show in September of 2011 after 25 years.
    This year’s Forbes magazine list of the world’s richest people estimated her wealth at almost 2.5 billion dollars.
    She founded the Oxygen media company, the Oprah’s Angel Network charity and the Harpo film, television and radio production company. She also started O, the Oprah Magazine, and the list goes on. She has starred in several films and helped launch entertainment careers.
    Oprah is getting more attention right now because of a new book. The writer, Kitty Kelley, is known for writing biographies of famous people without their approval.
    Oprah Winfrey was born in the small town of Kosciusko, Mississippi. She has said that her family was very poor and that she had cockroaches for pets. Kitty Kelley says some family members have disputed those statements.
    Oprah Winfrey has not commented on the claims in the book.
    As a teenager she went to live with the man she considers her father. Vernon Winfrey was supportive of her and her education. She became an excellent student and popular among her classmates.
    Oprah Winfrey has said she is who she is today because of Vernon Winfrey. She went on to Tennessee State University where she earned a degree in speech and performing arts.
    Oprah Winfrey became engaged to Stedman Graham in 1992 but they have not married.