In her new book, "We the Women," CBS News' Norah O'Donnell tells the overlooked stories of women who have helped shape our nation, from the single female whose name appears on the Declaration of Independence, to the first Black woman to argue a case before the Supreme Court. O'Donnell talks with correspondent Mo Rocca about being shocked by how much she didn't know of these women's contributions; the role of women in journalism today; and why she is optimistic about the future.