According to the Encyclopaedia Britanica, the Constitution is codification establishes the rules and
principles of an autonomous
political entity. In the case of countries, this term refers specifically to a national constitution defining the fundamental political principles, and establishing the structure, procedures, powers and duties, of a
government. Most national
constitutions also guarantee certain rights to the people. The term constitution can be applied to any overall law that defines the functioning of a government, including several historical constitutions that existed before the development of modern national constitutions.
Constitutions concern different kinds of political organizations. They are found extensively in regional government, at supranational (e.g., European Union), federal (e.g., United States Constitution), state or provincial (e.g., Constitution of Maryland), and sub national levels. They are also found in many political groups, such as political parties, pressure groups, and trade unions.
For this purpose, you can visit
Website Constitution Society.This website is presenting a lot of material to study the Constitution in countries who shaped Republic. You can read books, and classical political constitution.
Some of them may not be foreign to those who have interested in political science, such as
The Code of Hamurabi (1760 BC from the Babilonia),
Magna Carta (1215, books of JJ Rousseau), until The Modern of U.S. Constitution.