Read the preamble to the Constitution.

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.

In the preamble, the phrase “establish Justice, insure domestic Tranquility” means

to improve the government system and structure.
to create a system of laws for internal peace.
to identify the seat of power in the government.
to install this government system for the nation.

preamble to the Constitution was the introductory part of the statute that stated its purposes, aims and the goals of having a constitution. It is the opening statement to the United States Constitution. The preamble explains the reasons why the Framers of the Constitution made our government a republic. By doing this, the founding fathers replaced the Articles of Confederation.In the preamble, the phrase “establish Justice, insure domestic Tranquility” means To create a system of laws for internal peace. Generally preamble is an introduction or an introductory statement in a document which states the reasons for the rest of the document. An example of preamble is the beginning of the Constitution.