Constitutional History of Himachal Pradesh

• 15 April 1948 - The Himachal Pradesh was constituted as a Chief Commissioner’s province.
• 6 Sep 1951 - Himachal Pradesh became a Part 'C' State under Part 'C' State's Act, 1951. Himachal Pradesh was brought under a Lieut. Governor with 36 members Legislative Assembly.
• November 1951 – Elections to the 36 member Legislative assembly held.
• 1 March 1952 – Chief Commissioner was replaced by a Lieut. Governor.
• 24 March 1952 – Dr. Yashwant Singh Parmar was sworn in as head of popular ministry.
• 1 July 1954 – Part C state of Bilaspur was merged with Himachal Pradesh.
• 1 November 1956 - Himachal Pradesh became a Union Territory under an administrator with the designation of a Lieutenant Governor. The Territorial Council was formed under the Union Territories Act.
• 1 July 1963 – The Himachal Territorial Council was converted into a Legislative Assembly and a popular ministry headed by Dr. Y.S. Parmar was sworn in. (14th Constitutional Amendment)

• 1 November 1966 – The Government of India decided to integrate with Himachal Pradesh the Punjab Hill Areas which were viz. the districts of Kangra, Shimla, Kullu and Lahaul-Spiti, Nalagarh area of Ambala district, parts of Una tehsil of Hoshiarpur district and of Pathankot tehsil of Gurdaspur district.
• 18 December 1970 - The State of Himachal Pradesh Act was passed by Parliament.
• 25 January 1971 – Himachal Pradesh as a state came into being and emerged as the eighteenth state of the Indian Union.