It is well to take a step back from specialized histories and treatises, in order to appreciate the full scope and grandeur of our constitutional system. All of the books below are great resources to peruse, to gain historical perspective.
Congressional Quarterly, Inc. Guide to Congress. 6th ed. Washington, DC: CQ Press, 2008.
Nelson, Michael, ed. Guide to the Presidency. 4th ed. Washington, DC: CQ Press, 2008.
Biskupic, Joan and Elder Witt. Guide to the U.S. Supreme Court. 3rd ed. Washington, DC: Congressional Quarterly, 1997.
Bacon, Donald, Roger H. Davidson, and Morton Keller, eds. The Encyclopedia of the United States Congress. New York: Simon & Schuster, 1995.
Levy, Leonard W. and Louis Fisher, eds. Encyclopedia of the American Presidency. New York: Simon & Schuster, 1994.
Hall, Kermit, James W. Ely and Joel B. Grossman, eds. The Oxford Companion to the Supreme Court of the United States. 2nd ed. New York: Oxford University Press, 2005.