The Constituent Assembly began its work of drafting India's Constitution in the winter of 1946. More than three years later, on 26 January 1950, the Constitution came into effect, with the day celebrated every year since as Republic Day. A few provisions related to citizenship, elections, and provisional parliament were already in force from 26 November 1949 – the day the Assembly adopted the Constitution. But the Assembly deliberately chose 26 January as the day the Constitution would come into effect as a whole. The day was chosen to commemorate the Purna Swaraj Declaration of 1930.

Two days before Republic Day, on 24 January 1950, the Assembly sat for the last time, which also happened to be the only sitting in the month of January 1950. The first item of the agenda was the national anthem and the national song. Rajendra Prasad, the Chairman of the Constituent Assembly, stated that instead of adopting the national anthem formally through a resolution, it would be better if he just made a statement:

The composition consisting of the words and music known as Jana Gana Mana is the National Anthem of India, subject to such alterations in the words as the Government may authorise as occasion arises...

Rajendra Prasad swearing in as President
Image Credits: news18

Some members had some minor queries, which were dispensed with shortly. Next, H. V. R. Iyengar, the Returning Officer and the Secretary of the Constituent Assembly, announced the unanimously election of Rajendra Prasad as the President of India – there were no other nominations. Jawaharlal Nehru was the first to rise up and congratulate Prasad, remarking:

..Not only have we had experience of your able leadership during these three years of great difficulty but many of us have known you for three and thirty years or so as a soldier of India, ever in the forefront of the battle for freedom. (Cheers). So, we welcome you Sir, as our leader, as the Head of the Republic of India, and as a comrade who has faced without flinching all the crisis and troubles that have confronted this country during the past generation...

Several members delivered speeches congratulating Prasad including Sardar Vallabhbhai PatelB. DasH. C. Mookerjee, and  Hussain Imam. Humbled by all the praise, the President requested members to keep their congratulatory speeches short. He further expressed his gratitude towards all the members for bestowing him with the responsibility, while also drawing attention towards the challneges that still remained.

Constituent Assembly Members signing the Constitution
Image Credits: Hindustan Times

The members of the Assembly then signed three copies of the Constitution: an English hand-written and illuminated copy, an English print copy and a hand-written copy in Hindi. Before concluding the proceedings, Algu Rai Shastri pointed out the plight of the secretarial staff assisting the Assembly, who would find themselves unemployed after the Assembly adjourned. The President assured him that all efforts will be made to accommodate them in other governmental departments. 

The day's sitting ended with Purnima Banerji leading members to sing Jana Gana Mana, followed by Lakshmi Kanta Maitra doing the same for Bande Mataram.

The Assembly then adjourned. Two days later, the Constitution came into force and transformed India into a Republic.