1. Origin
The Constitution was adopted on November 26, 1949, while it came into force on January 26, 1950. The first session of the Assembly was held on January 24, 1950, which unanimously elected Rajendra Prasad as the President of India.

2. The time it took
The Constituent Assembly took almost three years (two years, eleven months and seventeen days) to complete the historic task of drafting the Constitution for Independent India. The Constituent Assembly had 284 members, out of which 15 were women. The Drafting Committee submitted the draft in November 1949, after which they took three more years to complete it.

3. Drafting committee

The all-important Drafting Committee, which bore the responsibility of drafting the Constitutional document was formed on August 29, 1947. Its members were:
BR Ambedkar
Diwan Bahadur Sir Narasimha Gopalaswami Ayyangar
KM Munshi
Sir Syed Muhammad Saadulla
N Madhav Rao
DP Khaitan (T Krishnamachari, after Kahitan's death in 1948)

4. A labour of love
The Constitution of India was not typeset or printed, but was handwritten and calligraphed in both English and Hindi. Prem Behari Narain Raizada (Saxena) of Delhi  wrote the entire Constitution in a flowing italic style in the best calligraphic tradition of our country. The task was completed in 6 months. 254 pen-holder nibs were used and number: 303 nib was used for this calligraphy. It was decorated by artists from Shantiniketan including Beohar Rammanohar Sinha and Nandalal Bose.

5. The National Emblem

On January 26, 1950, India also adopted Sarnath, the Lion Capital of Ashoka with the wheel, bull, and horse as the national emblem of India.

6. World’s Longest Constitution

The Constitution of India is considered the world’s lengthiest document because originally it contained 395 Articles divided into 22 parts and B Schedules. At present it contains 448 Articles and 12 Schedules as a result of around 100 amendments effected in the Constitution since 1950.

7.  The Indian Constitution draws bits and pieces from other world Constitutions like:
A.      Irish Constitution – Directive principles have been derived from the Irish constitution
B.      British Constitution – Parliamentary form of government with a Cabinet system having accountability to the lower House and Parliamentary privileges.
C.       US Constitution – Fundamental rights, the Supreme Court, the post of  Vice-President
D.      Canadian Constitution – The federal system, Union-state relations and distribution of powers between the Union and the states
E.       Australian Constitution – The concurrent list, provision of trade and commerce
F.       German (Weimer) Constitution – Emergency provisions 
G.    French Constitution - The concepts of liberty, equality and fraternity
H.     Japan Constitution - The law on which the Supreme Court functions

8. India, the Union

It was BR Ambedkar, who clarified that India was a Union and no state had the right to secede from the Union. The first article of the Constitution says, “India, that is Bharath, shall be a Union of states.”

9. Significant addition

The Preamble of the Constitution of India states that India is a Sovereign Socialist Secular Democratic Republic. The term “Socialist” was added later in 1976 through the Constitution’s 42nd Amendment Act, 1976.

10. Original hand-written copies of Constitution

The original hand-written copies of the Constitution are kept in helium-filled cases in the Library of the Parliament House.