Article IV of the U.S. Constitution established that the Union could create and admit new states, but it wasn't until the Northwest Ordinance of 1787 that a process for that admission was determined. One of the requirements is that the future state must have a constitution that provides for a republican government, one that is run by elected representatives. Most of them follow the form of the U.S. Constitution closely, leading to similarities between the documents.

Structure of Government

The state constitutions provide a framework for government by elected representatives of the citizens. Like the U.S. Constitution, state constitutions divide the power of the government into executive, legislative and judicial branches. In both cases, the executive branch -- the president or the governor -- is responsible for implementing laws passed by the legislative branch. Both the U.S. Constitution and the state constitutions describe the organization of the relevant court structure, as well. Other sections of both federal and state constitutions also establish how the political entity will raise and spend money.

Checks and Balances

Both the U.S. Constitution and state constitution contain stipulations that help ensure cooperation between the branches and the means to prevent one branch from becoming strong enough to overwhelm another. In addition, the documents at both levels have provisions for amending, or changing, the constitution as the citizens and their representatives feel it necessary.