The post below is from 2011 but I’m bumping it up with the addition of this excellent video of the project to archive her work.
Vivian Maier (February 1, 1926 – April 21, 2009) was an American street photographer born in New York City. Although born in the U.S., it was in France that Maier spent most of her youth. Maier returned to the U.S. in 1951 where she took up work as a nanny and care-giver for the rest of her life. In her leisure however, Maier had begun to venture into the art of photography. Consistently taking photos over the course of five decades, she would ultimately leave over 100,000 negatives, most of them shot in Chicago and New York City. Vivian would further indulge in her passionate devotion to documenting the world around her through homemade films, recordings and collections, assembling one of the most fascinating windows into American life in the second half of the twentieth century.
A more complete biography on Vivian Maier here.
Check out her portfolios including one of self portraits.