Campbell's Chicken Noodle Soup turns 80 this year. It's a safe bet to assume most Americans have been served a bowl full of the soup at least once in their lifetime. While the soup's contents might not have changed, its advertising certainly has. Take a look at some of these hilarious vintage print ads dating back to 1934 . . . and see how long the "M'm! M'm! Good!" slogan has been around.