Within few years of independence & political integration, agitations began emerging across India in localized groups demanding for creation of smaller provinces or states on linguistic basis. Nehru was against such an idea because he feared that it would shift the loyalty of citizens from the country towards their linguistic groups and thereby affect national unity.
However, the agitations continued to grow and the demand for a separate state for Telugu speaking people started gaining more momentum compared to others. Potti Sriramulu, an ardent Gandhian, spearheaded the Telugu movement and he undertook a “fast unto death” in Oct 1952 to carve out a Telugu state out of Madras Presidency. Unfortunately, he sacrificed his life and breath his last on the 58th day of his fast which in turn led to widespread violence due to emotional outbursts. As the violent aftermath grew at an alarm rate by the day, the Govt had no choice but to accept the demand and created a new state called Andhra in 1953.
This led to further motivation for the other localized groups who were demanding for carving out states based on their respective linguistic groups. To avoid being impartial & avoid large scale sabotage, the Govt formed the “States Reorganization Commission” in 1953 which did intensive surveys of hundreds of districts & existing state boundaries along with the linguistic distribution and finally came up with a boundary reform plan.
The case of Andhra during 1956 reorganization was relatively tricky due to the complication involved in dividing the existing Hyderabad State and merging it with newly formed Andhra State. On linguistic basis, Hyderabad State was divided into 3 parts. The western part which constituted Kannada speaking region was joined into Mysore State, the north western part joined into Maharashtra & the eastern part which was called the Telangana region was merged into Andhra State, thereby leading to a whole new state Telugu state called Andhra Pradesh.
The findings were consolidated to form a report which was passed as “States Reorganization Act” in 1956 and as a result, the map of India was redrawn to accommodate a total of 14 states & 6 Union territories.
TIME magazine archive reporting Sriramulu’s fast & death:
Report of the States Re-organisation Commission
General info in Wikipedia: