Juliia Cameron was an amateur photographer in the truest sense of the word. The body of work she produced in the 1860's and 70's helped shape what we think of as photography today. Many of her images have an iconic property that is still relevant 150 years later.

The Getty has released a free cataloge of her work. Get it while you can.
http://www.getty.edu/publications/virtuallibrary/0892366818.html