The reference series, "Landmark Events in US History", uses both contributed essays from eminent scholars and excerpts of primary source documents with explanatory headnotes to focus on critical events in American political history and explain why they continue to play such a vital role in the political evolution of the United States. The set includes: "The Declaration of Independence", "The Louisiana Purchase", "Marbury versus Madison", "Watergate and the Resignation of Richard Nixon" and "The Voting Rights Act: Securing the Ballot".