The endearing, angry, and heartbreaking letters the world sent to Neil Armstrong after Apollo 11

Neil Armstrong spent much of his life after the moon landing shunning attention. If people had to praise, he encouraged them to appreciate all of his work, not just the historic landing. But his one small step affected people around the world in profound ways, and tens of thousands of people felt compelled to write him personal letters. The contents of those letters -- and Armstrong's responses -- are a fascinating piece of American history. Jeff Glor reports.