Maier was an American photographer. She worked for about forty years as nanny, mostly in Chicago, pursuing photography during her spare time. She took more than 150,000 photographs, primarily of the people and architecture of Chicago, NYC, and LA.

Maier's photographs were unknown and unpublished during her life. A Chicago collector acquired some of her photos in 2007, while two other Chicago-based collectors also found some of Maier's prints and negatives in her boxes and suitcases around the same time. Maier's photographs were first published on the Internet in July 2008 but the work received little response. In October 2009, Maier's photographs were posted on Flickr, and went viral, with thousands of people expressing interest. Her work subsequently attracted critical acclaim, and have been exhibited around the world. See more of her photographs here.