The correct answer is the Constitution.
The Constitution of the United States continues to be the guiding pattern for many constitutions abroad, and it is still perceived as the fundamental point of reference. The most adapted passages of the U.S. Constitutions are the principles of the rule of law, separation of powers and recognition of individual rights.
Some similarities to the U.S. Constitution can be found in the Constitutions of the following countries: Australia, Canada, Germany, Switzerland in Europe. In Central America: Argentina, Brazil, Mexico, Peru and Venezuela. In Africa: Liberia, Ethiopia, Zimbabwe. In Asia: Bangladesh, China, Vietnam and the Philippines.