The Rise and Fall of the American Century: The United States from 1890-2009 by William H. Chafe

This book presents a fairly cogent overview of American history from 1890 to 2009 (barely--it saves two pages for the recession and President Obama's election). The point of view is fairly liberal (especially in the latter chapters), and while it covers a variety of social, economic, political, and military history, if there's one aspect of American history it focuses on, it's the presidency. It reads a bit like a textbook, and is thus a little dry, but it would be a good and quick overview for anyone who wants to catch up on modern, American history.