I am writing a paper, and my research topic is the American public opinion of Fidel Castro during the Cuban Missile Crisis as examined through print media. This extends to newspaper articles/headlines, magazine articles/covers, and political cartoons from that time period. I have had decent success finding print articles through JSTOR, my university database, and others but am having a tough time finding good resources for political cartoons. Any recommendations?
I can't be all that sure it will be fruitful but have you tried back-issues of the New Yorker?
Edit: or for that matter just using the microfilm collections at your library? I assume back issues of major newspapers will still be on microfilm for the most part? I may be behind the times. Looking for cartoons might be one of the few such instances I can think of where scrolling through microfilm might be easier than doing a digital search.
There are specialized databases which your university should have access to, however they usually involve keyword searches and are not purely databases of political cartoons as such.
One suggestion might be looking up associations of American cartoonists to see if they know of any resources specific to political cartoons.
Another idea would be to contact specialists in the Cuban Missile Crisis by looking their university accounts up online to ask them if they know of any good places to start.
Sorry I can't be of more help.