Besides My Photo Stream on Flickr here are some links to other photo sites that I can recommend:
Photo Galleries and alike
- Vivian Maier by John Maloof
Vivian Maier – Her Discovered Work - Viggo Rivad, 1922-2016
- American Pictures by Jacob Holdt
- Tina Modotti, eg. on Pinterest
- The Wonderful World of Albert Kahn
Book+DVD by BBC and Albert Kahn Museum - Erik Johansson: Surreal Photography
- Costică Axintes archive on Flickr
Romanian pictures, approx 1930-1950 - World Press Photo
- ActiveStills.org
- How the Other Half Lives by Jacob Riis
see also Authentic History - KORTAL: COWIs KortPortal, air-photo maps of Denmark
incl complete 1954 photo set by US AirForce (text in Danish only)