They're commonly called "the nouveau riche." Snubbed by New York's old-money families, these ambitious new millionaires, along with their daughters, set their sights on England, and quickly gain entry into the highest levels of the British aristocracy. Join "Downton Abbey" star Elizabeth McGovern as she explores the first transatlantic marriages of the late 1800s. Some will be inspired by love. Some are destined to be simply crude dollar-for-title deals. All of them, collectively, will change the course of history.

Marriages between the daughters of new-money Americans and a cash-strapped British aristocracy hit its stride by 1895. But these unions come at a price, financially and emotionally. While some women find true love overseas, others, like Consuelo Vanderbilt, find themselves mired in misery, loneliness and scandal. Host Elizabeth McGovern reveals how their stories inspired the hit series "Downton Abbey." Then, she explores how the daughters of America's wealthy industrialists survived, and even thrived, in their new aristocratic surroundings.

By the 1930s, the legacy of America's millionaire princesses paves the way for a new generation of American women to enter, and transform, the British ruling class. Some will leave their marriages to explore independent destinies, one will trade charisma instead of wealth to marry into royalty, and one will unwittingly bring about the greatest royal crisis of the 20th century. Witness stories of character and courage as these women escape loveless marriages, break barriers, create their own happy endings and make history.