There were 203 million people living in the U.S. in 1970 -- and almost 8 million of them lived in the country's biggest city, New York City. It's the year first lady Melania Trump was born, as was director M. Night Shyamalan and singer Mariah Carey. It's the decade that gave us the pet rock and "Pong," as well as Stephen Hawking's theories about the Big Bang and the existence of black holes. Think you know '70s trivia? Dream on!