The United States Holocaust Memorial Museum‘s Photo Archives is mainly an in-person attraction, but more than 30% of their 100,000 historical photographs are available for search online. In the online search, you can select the “Public Domain” filter under the “Photo Usage Rights” section and you now have access to 3,498 (at the time this post was written) photos! The USHMM photos can be categorized, in the broadest sense, into people, locations, and documents. There are the expected photos showing the horrors of the extermination camps, but there are also photos of people waiting to be sent to camp–which are also quite eerie–and even photos of notable famous figures, such as the journalist Dorothy Thompson. Location photos range from, once again, the aerial and first-person views of the camps to shots of sanctuaries in synagogues. Lastly, the documents include things such as maps and letters, useful for research and gathering facts.