#405 Mona Lisa at the Metropolitan Museum of Art

Mona Lisa, Leonardo da Vinci's stoic portrait and one of the most valuable paintings on earth, came to America during the winter of 1963, a single-picture loan that was both a special favor to Jackie Kennedy and a symbolic tool during tense conversations between the United States and France about nuclear arms.

Its first stop was the National Gallery in Washington DC, where over a half million people spent hours in line to gaze at the famous smile.

Then, on February 7, 1963, she made her debut to the public at the Metropolitan Museum of Art, hosted in the medieval sculpture hall for a month-long exhibition that would become one of the museum's most attended shows.

On that first day, thousands lined up outside in the freezing cold to catch a glimpse of the iconic painting. By week's end, a quarter of a million people had visited the museum to see the Italian masterpiece.

PLUS: What's it like guarding precious and iconic works of art like the Mona Lisa? Patrick Bringley, a former guard at the Metropolitan Museum of Art, joins Greg and Tom in the studio to discuss his new book All The Beauty In The World: The Metropolitan Museum of Art and Me, recounting a decade of purpose, sorrow and epiphany while working in America's largest museum.