Vivian Maier was a nanny for over 40 years in Chicago. Little did anyone know that she had a secret passion for photography, and spent years (and hundreds of thousands of photographs) documenting streetscapes from the 1940s up through the 1970s. She had a natural ability to capture American life and moments (although she did take photos abroad as well), many of which offer a telling look into vintage New York or vintage Chicago.

Her work was only unearthed randomly by a real estate agent/historian in 2007, two years before her death. The discovery of Maier’s enormous body of work has now placed her as one of the best street photographers of the mid-century.

If you’re intrigued, there’s a documentary about Maier and the discovery of this treasure trove. A new book of her work, Vivian Maier: Self-Portraits, has also just been published. And if you’re in the L.A. area, there’s an exhibition of (largely) unseen photographs, on view at Merry Karnowsky Gallery beginning December 14.

The following is a selection of beautiful, telling, and haunting photographs from that exhibition.