They were three leading ladies, American heiresses who came to England and had a major impact on the fashion world, interior design, and even Parliament. Elizabeth McGovern's exploration of the women who inspired the acclaimed series "Downton Abbey" brings us the stories of Nancy Astor, Nancy Lancaster and Pauline de Rothschild. They crossed the Atlantic for very different reasons and embarked on very different paths to fame, but each woman shared one attribute: the desire to stand up and be heard, and they were.