Political posters are powerful tools of persuasion and control via striking visual imagery. Scholarly interest in the strong visual images draws many researchers to Hoover's voluminous poster collection. Others mine more popular parts of the collection, such as this CBC article on National Doughnut Day, which highlights posters of US troops receiving doughnuts and coffee from Salvation Army doughnut lassies during World War I.

With the recent addition of more than 4,000 images from Germany, the Hoover Institution’s searchable online poster database now provides access to some 22,000 images of political posters in Hoover’s poster collection.

With more than four thousand images from the United Kingdom having been recently added, the Hoover Institution’s online, searchable poster database now has some eighteen thousand images of political posters from its collection.