Marilyn Monroe, who infamously sang "Happy birthday, Mr. President" at the age of 35, would be celebrating her 83rd birthday today. In honor of her birthday, LIFE.com released 15 never-before-published photos of Marilyn when she was only 24 years old and far from famous. Her star quality shined through at a young age, but when the photographer sent the photos to LIFE in 1950, the magazine wired back: "Who the hell is Marilyn Monroe?" Now the magazine is sharing the pictures — almost 60 years later!
Happy birthday, Marilyn.