In modern constitutional history, the concept of a single written national constitution first emerged in which country?

Introduction / Context:
Many exam questions compare the Constitution of India with other constitutions in the world. One common fact relates to which country first adopted a modern written national constitution. This question tests whether the learner knows that the earliest widely recognised example of such a constitution is associated with a particular country, whose model influenced later constitution making processes around the world, including India.

Given Data / Assumptions:

The question asks about the origin of the concept of a written national constitution.
Four countries are offered as choices: United States of America, France, United Kingdom and Switzerland.
The learner is assumed to have a basic understanding of comparative constitutional history.
There are no calculations or legal technicalities required; this is a direct factual question.

Concept / Approach:
The approach is to recall that the United States of America adopted its written constitution in 1787, which came into effect in 1789. This document is widely regarded as the first modern written national constitution. The United Kingdom still has an uncodified or unwritten constitution made up of statutes, conventions and judicial decisions. France and Switzerland developed written constitutions later. Because the question is about where the concept of a written constitution was first born in the modern sense, the correct answer is the United States of America.

Step-by-Step Solution:
Step 1: Recall that a written constitution means a single formal document or set of documents that serves as the supreme law of the land. Step 2: Recognise that the United States Constitution of 1787 is often cited as the earliest such modern written national constitution. Step 3: Note that the United Kingdom does not have a single codified written constitution even today; its constitutional rules are spread across various sources. Step 4: Remember that France and Switzerland adopted written constitutions after the American example and after their own revolutionary experiences. Step 5: Compare the options and see that only the United States of America fits the historical description provided in standard references. Step 6: Therefore, choose United States of America as the correct answer.

Verification / Alternative check:
One can verify by consulting any introductory textbook on comparative constitutional law or political science. These texts usually highlight the United States Constitution as the first modern written constitution and discuss its influence on later constitutions, including the French, Swiss and Indian constitutions. They also emphasise the unique uncodified nature of the British constitutional system. Since multiple reliable sources agree on this historical point, it is safe to accept United States of America as the correct option.

Why Other Options Are Wrong:
France: Adopted important written constitutions after the American example, particularly following the French Revolution, but was not the first in the modern sense.
United Kingdom: Still operates under an uncodified constitution and therefore does not fit the description of the origin of a single written constitution.
Switzerland: Known for federalism and direct democracy, but its written constitution came later than the American document.

Common Pitfalls:
Some learners wrongly associate written constitutions with any country that has a strong legal tradition or a famous revolution. This can lead them to choose France or the United Kingdom by mistake. Others may not distinguish between early charters, such as Magna Carta, and a full written national constitution. To avoid these mistakes, it is useful to remember that Magna Carta was a charter within a kingdom, while the United States Constitution of 1787 is widely considered the first modern written national constitution. Keeping this timeline in mind helps answer similar questions correctly.

Final Answer:
The concept of a modern written national constitution first emerged in the United States of America.