Study Stack: Presidents of the United States offers information on the presidents, including their political affiliations and the number of years they spent in office. StudyStack.com is an educational tool that helps students memorize tables of information on any subject. Like flashcards you can review information at your own pace. StudyStack provides multiple ways for you to quiz yourself on the information that you are trying to memorize - flashcards, matching, and study table. Enter data once and all the tools will use that data. Use the existing data sets or add your own to share with others.