Timeline of reorganization & name changes of UP
1807	Ceded and Conquered Provinces
14 Nov 1834	Presidency of Agra
1 Jan 1836	North-Western Provinces
3 Apr 1858	Oudh taken under British control, Delhi taken away from NWP and merged into Punjab
1 Apr 1871	Ajmer, Merwara & Kekri made separate commissioner-ship
15 Feb 1877	Oudh added to North-Western Provinces
22 Mar 1902	Renamed United Provinces of Agra and Oudh
3 Jan 1921	Renamed United Provinces of British India
1 Apr 1937	Renamed United Provinces
1 Apr 1946	Self rule granted
15 Aug 1947	Part of independent India
24 Jan 1950	Renamed Uttar Pradesh
9 Nov 2000	Uttaranchal state, now known as Uttarakhand, created from part of Uttar Pradesh

	Million Plus Cities of Uttar Pradesh by population (2011 Census)
Name	Population	Name	Population
Kanpur	2,920,067	Lucknow	2,901,474
Ghaziabad	2,358,525	Agra	1,746,467
Varanasi	1,435,113	Meerut	1,424,908
Allahabad	1,216,719	Bareilly	979,933

Population Growth
Census	Pop.	%±
1951	60,274,000	—
1961	70,144,000	16.4%
1971	83,849,000	19.5%
1981	105,137,000	25.4%
1991	132,062,000	25.6%
2001	166,198,000	25.8%
2011	199,581,477	20.1%
Source:Census of India

24 January 1950

Uttar Pradesh (/ˈʊttˈər prəˈdɛʃ/), abbreviated as UP, is the most populous state in the Republic of India as well as the most populous country subdivision in the world. The state, located in the northern region of the Indian subcontinent, has over 200 million inhabitants. It was created on 1 April 1937 as the United Provinces during British rule, and was renamed Uttar Pradesh in 1950. Lucknow is the capital city of Uttar Pradesh. The main ethnic group is the Hindi people, forming the demographic plurality. On 9 November 2000, a new state, Uttarakhand, was carved out from the Himalayan hill region of Uttar Pradesh.

The state is bordered by Rajasthan to the west, Haryana, Himachal Pradesh and Delhi to the northwest, Uttarakhand and Nepal to the north, Bihar to the east, Madhya Pradesh to the south, and touches the states of Jharkhand and Chhattisgarh to the southeast. It covers 243,290 square kilometres (93,933 sq mi), equal to 7.33% of the total area of India, and is the fourth largest Indian state by area. Hindi is the official and most widely spoken language in its 75 districts along with English. Uttar Pradesh is the third largest Indian state by economy, with a GDP of ₹9,763 billion (US$150 billion) and the fourth-largest contributor to India's net domestic product. Agriculture and service industries are the largest parts of the state's economy. The service sector comprises travel and tourism, hotel industry, real estate, insurance and financial consultancies.

...
Wikipedia