The Preamble to the Constitution mainly serves as an introductory statement that outlines the reasons the U.S. Constitution was written and the values it represents. Although the Preamble provides much meaning to the Constitution, the Supreme Court ruled in 1905 that it has no bearing on law.
The Preamble is technically only one sentence, albeit a long one consisting of 52 words. However, there are many themes covered in this one sentence, including liberty, justice, equality, posterity, domestic tranquility and security in the form of common defense.
The Preamble was written by Pennsylvania delegate Governor Morris during the final days of the Constitutional Convention of 1787. As a member of the Committee of Style, Morris, along with James Madison, Alexander Hamilton, Rufus King and William S. Johnson, also helped to draft the final text of the Constitution. The Constitution, along with the accompanying Preamble, was signed on September 7, 1787 by 38 of the 41 delegates who had attended the convention.
After much debate and compromise, the U.S. Constitution eventually achieved the nine necessary ratifications it needed to become official on June 21, 1778, almost a year after it was signed. It became the official basis for the U.S. government on March 4 of the following year.