Unused Plastichrome card P36775.  We sometimes think we could open a new category called “The …est” and somehow each postcard would fit inside.  Why do we say this here?  Because this card’s caption–probably written in the 1950s or early 60s–says the Kentucky Dam is “Forming the largest man made lake in the world.”  We Googled.  It’s not even in the Top 10 now.  Grade: 1