The concept "1" refers to Article 1 of the Constitution of India, a foundational provision that defines the nation's name and territorial structure. It was debated by the Constituent Assembly on November 15 and 17, 1948, and September 17 and 18, 1949, and came into effect with the Constitution in 1950. The primary problem it solved was establishing the legal and political identity of the newly formed republic.
The key mechanism is laid out in three clauses. Article 1(1) declares, "India, that is Bharat, shall be a Union of States". The phrase "Union of States" was deliberately chosen by the framers to clarify that the constituent states do not possess the right to secede, unlike a loose federation. Article 1(2) specifies that the States and their territories are those listed in the First Schedule of the Constitution. Article 1(3) defines the territory of India as comprising the territories of the States, the Union Territories specified in the First Schedule, and any other territories that may be acquired.
Article 1 is the first of four articles in Part I of the Constitution, which deals with The Union and Its territories. It is intrinsically connected to Article 2, which provides the mechanism for the admission or establishment of new States. While the text of Article 1 itself has not been amended since 1950, the First Schedule it references is frequently updated to reflect changes in the nation's political geography. For instance, the conversion of the State of Jammu and Kashmir into two Union Territories in 2019 altered the list of territories defined by Article 1.