America's 250-year history features prominent men who built and shaped the nation. Less is known about the women whose contributions were just as important. In her new book, "We the Women: The Hidden Heroes Who Shaped America," Norah O'Donnell writes about 35 remarkable women, each of whom played pivotal roles in influencing the country we live in today. Watch Amna Nawaz's interview with O'Donnell. | PBS NewsHour