According to the preamble, why was the constitution written

The Constitution of the United States established America's national government and fundamental laws, and guaranteed certain basic rights for its citizens. It was signed on September 17, 1787, by delegates to the Constitutional Convention in Philadelphia

According to the preamble, the United States Constitution was created to guarantee Justice, Domestic Tranquility, Common Defense, the General Welfare and the Blessings of Liberty to every American citizen through the years.

Explanation:

After the emancipation of the Thirteen Colonies, the Constitution of the United States was soon discussed after the victory against the English settlers. On that occasion there were the formation of two factions divided between the federalists and republicans. The former preached the strengthening of central power in order to preserve the political union of states. The Republicans, however, believed that the autonomy of states could not be submitted to the central government. But both groups wanted the same thing as ensuring that the population had access to justice, domestic tranquility, common defense, general well-being and the blessings of freedom.

no because we were not ready for war

i would say that the politicial parties from state to state varies.