Several museums with extraordinary holdings in American art have all or a large percentage of their collections online. You usually search these works by artist, title, nationality, date, and subject matter. Worth consulting are:
Images are core resources in art history. The links on this page direct you to important Web pages for exhibitions and museums as well as resources to which the Libraries subscribe. The Libraries' collection of books and journals also offer numerous images for the researcher, although not all are indexed and listed. Contact me for additional assistance.
JSTOR provides a searchable database of more than four million images.
Selected recent American art exhibitions have had significant online components with not only illustrated checklists but also copious information on works and themes surveyed. A few examples include:
The following are three of the more useful sites for delving into visual materials not necessarily by fine artists but rather materials closely related to themes explored in American art and cultural history. The materials are critical in understanding visual traditions and political, religious, economic, gendered, and other contexts. You may find sheet music covers, mass-reproduced posters, trade photographs, and so on with subjects related to your thesis. Art historians often reproduce such items in their scholarship as examples and corroboration of trends and clarification of popular and intellectual appeal.