Art History

Museums may not have their collection searchable or optimized for Google. However, Metropolitan Museum of Art or Smithsonian have great web sites.

This links to their open access collection.

Over 87,000 images. "The Getty makes available, without charge, all available digital images to which the Getty holds the rights or that are in the public domain to be used for any purpose. No permission is required." (Getty website quote)

An older site, but they do allow for Creative Commons searches. Also, look to Morguefile, and other types of photosharing communities. But watch copyright.

Other - you can find collections of materials in many different sites. Essentially, any large, robust organization may have a collection.

Advancing Women Artists Foundation, an American not-for-profit 501(c)(3), is committed to identifying, restoring and exhibiting artwork by women in Florence’s museum storages

peer reviewed, open access online encyclopedia created in conjunction between the Society of Architectural Historians and the University of Virginia Press.

A rich source of images, with a mix of user uploads and organizations.

Collaborative Index of 1.2 million bibliographic records of periodicals, books, exhibition and auction catalogues, published between 1910 and 2007

Through Internet Archive. " the records of artists, galleries, museums, and arts organizations to conduct historical research and to understand and contextualize contemporary artistic practice. ... more than 40 art libraries spent the last 3 years developing a collective approach to preservation of web-based art materials at scale. "