Compare UK and US constitutions

US Constitution

The US Constitution was a result of the constitutional convention that took place in 1787. It’s the supreme law of the United States establishing the country’s national structure and political processes.
It’s primarily divided into seven articles, each focusing on different aspects of governance namely the Legislature, Executive, Judicial, relationship amongst states, the amendment process, supremacy and ratification.
The US Constitution embeds principles of separation of powers, with legislative, executive and judicial functions carried out by distinct branches.
It is a codified constitution, meaning it is written down in a single comprehensive document.

The Constitution has an amendments process outlined in Article V, which allows changes to the Constitution if ratified by three-fourths of the states.
There are currently 27 amendments to the US Constitution, the first ten of which are collectively known as the Bill of Rights.
Some key amendments include the First Amendment (ensuring freedom of speech, religion, and the press), the Second Amendment (right to bear arms), and the Nineteenth Amendment (giving women the right to vote).

US citizens are protected by the provisions embedded in the Constitution as well as the Bill of rights.
The First Amendment guarantees fundamental freedoms including freedom of speech, religion, assembly and the press.
The Fourth Amendment protects against unreasonable searches and seizures.

The Constitution operates on the principle of Federalism, distinguishing powers between the federal and state governments.
Another key principle is the separation of powers, where powers are shared among three branches of the government namely, Executive, Legislature, and Judiciary.
Checks and balances is another significant principle where each branch of government can limit the powers of the other branches.

The Constitution establishes a federal system of government where power is shared between the federal government and state governments.
The Tenth Amendment delineates the balance of power, reserving those not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.

Unlike the US Constitution, the UK doesn’t have a single constitutional document. The British Constitution is uncodified and is derived from various sources including statutes, conventions, and judicial decisions.
The US Constitution emphasises more on the separation of powers among the different branches of government, whereas the UK Constitution fosters an integration of powers, with the Prime Minister being a member of the legislature as well as the head of the executive.
Federalism is another major distinction, with the US having a federal system, whereas the UK follows a unitary system where Parliament holds supreme authority over the entire UK.