Researchers and designers often require a broad range of historical visual images. Below are some resources that serve as good starting places, though many of them are more focused on fine arts (rather than film stills and documentation). Note that some resources require off-campus access privileges.
AP Newsroom (formerly AP Images) contains millions of photographs dating from 1826 to present day from the Associated Press. Includes thousands of graphics, audio files dating from the 1920s, and news stories and headlines from 1997 to the present.