Digital Public Library of America (DPLA)
is a free “platform that enables new and transformative uses of our digitized cultural heritage. The DPLA’s application programming interface (API) and open data can be used by software developers, researchers, and others to create novel environments for learning, tools for discovery, and engaging apps.”
Digital Public Library of America involves more than 1,600 libraries, museums, and archives throughout the US.
DPLA has links to items over 13 million items. You type a query in the “Search the Library” window, then look through the results page and select which item you wish to view and you’ll be taken to the hosting institution.
It’s an easy way to search multiple institutions at once and have the best chance of returning a “hit.”