This site is a massive undertaking. The Library of Congress has been taking the first-hand accounts of U.S. Veterans from WWI, WWII, Korean War, Vietnam War, Persian Guld War and the conflicts in Afghanistan and Iraq. A good place to start is to click on View Featured Interviews. Interviews have been organized around a specific theme with as many of the wars represented as possible. They are constantly adding to the list of featured themes.
This breakdown of Billy Joel's song "We Didn't Start the
Fire" provides numerous links to various aspects of history
included in the song, including several presidents, social issues,
and foreign affairs.