The Original Constitution of the United States, the Articles of Confederation, was approved in 1781, but within a few years the Articles were replaced by the Constitution of the United States. Approximately seven decades late, the Confederate States of America wrote a constitution using the U.S. Constitution as a model. The three documents are used as a case study on constitutional rules as constraints on government. When compared to the Articles, the effect of adopting the Constitution was to relax constraints on the federal government. The Confederate Constitution added constraints to the U.S. Constitution, while retaining the same basic framework.