Richard Sakwa, The Rise and Fall of the Soviet Union (1999)
Here's a basic history from the Routledge Sources in History series.
Randy Shilts, And the Band Played On: Politics, People, and the AIDS Epidemic (2000)
This is the essential history of the rise of the AIDS epidemic in the U.S., documented by a reporter who was there in San Francisco for the whole awful affair. It's an important and incredible read for anyone interested in the subject.
Anders Stephanson, Manifest Destiny: American Expansion and the Empire of Right (1996)
Here's an essay on the idea of Manifest Destiny and westward expansion before and after the Civil War. This is just a starter among many possible resources.