Drafted in the summer of 1787 and ratified by 1788, the Constitution provides the framework for the government of the United States of America. This founding document consists of three main parts. The first part, the Preamble, explains the purpose of the Constitution and the federal government. The second part, the Articles, details how the government is structured and how the Constitution may be amended. The third part, the Amendments, lists the changes (i.e., amendments) to the Constitution.