From 1865 to 1945, a number of prominent marriages united American heiresses and members of the British aristocracy. In Informal Ambassadors, author Dana Cooper examines the lives and marriages of the American-born, British-wed Lady Jennie Jerome Churchill, Mary Endicott Chamberlain, Vicereine Mary Leiter Curzon, Duchess Consuelo Vanderbilt Balsan, and Lady Nancy Astor.