In September 2017, 230 years have passed since the entry into force of the Constitution of the United States of America – the Basic Law of the recently created independent state, which liberated itself from the colonial dependence on England by armed action. To the adoption of the Constitution preceded the adoption by the country's parliament – the Convention of two more constitutional laws – the Declaration of Independence (1776) and the Articles of Confederation (1781). The USA Constitution 1787 legalized the creation of a single union state – a federation, which was created by 13 former British colonies in North America, and since the beginning of the war with England (1775) – the states. The Constitution, which in the history of becoming not only American, but also world constitutionalism, became its forerunner, the first active constitution in the world, is rather small in scope: it has seven articles, which, however, are divided into sections. The basis of the construction of the federal state apparatus is the principle of the distribution of power – on the legislative, executive and judicial branches. Legislative power is conferred on the Congress, which consists of two chambers and elected by the citizens; executive power – the president, who is also elected by the citizens, but by the two-stage elections procedure; judicial – the Supreme Court, which is appointed by the president, but in agreement with the upper house of Congress – the Senate. All three branches of power mutually complement and control each other, which became a guarantee against possible dictates of one of them or the establishment of authoritarian, dictatorial power. It is also important that, unlike Europe, where at that time there were mostly absolute or semi-absolute monarchies, in the United States the Constitution introduced a republican form of government – both for the federation and for the states. The Constitution of 1787, with all its positivity and democracy, was not deprived of some of the shortcomings mentioned in the article. In particular, we mean silent preservation on the territory of the country of slavery, for which the delegates of all the southern states stood firmly, and eventually some politicians from the central and northern states. Becides that there was a complete disregard for the rights of the indigenous population – the Indians, who were not considered to be valuable people, but a «wild beasts», which must be destroyed. Perhaps the most important disadvantage of the Constitution was that there was a complete lack of a section on democratic rights and freedoms of citizens in its text, which soon became the pretext for several states to refuse ratification of the Constitution. Congressmans-legislators were forced to assure the citizens and the power of these states that in the near future they would supplement the text of the Constitution with the relevant section, and this was done. One can not but mention that the text of the Constitution can sometimes be interpreted differently, that is ambiguous, which in the future really led to misunderstandings between the US authorities, authorities and citizens, and so on. However, these disadvantages do not reduce the historic significance of the US Constitution.