Step 1: Understanding the Concept:
The question seeks to identify the key activist who undertook a fast-unto-death, which was a pivotal moment in the movement for the creation of states based on language in post-independence India.
Step 2: Detailed Explanation:
The activist was Potti Sreeramulu, a dedicated Gandhian freedom fighter. He undertook a fast-unto-death to demand the formation of a separate state for Telugu-speaking people from the then Madras Presidency. His fast began on October 19, 1952, and lasted for 58 days. He passed away on December 15, 1952. His death sparked widespread riots and protests in the Telugu-speaking regions, compelling Prime Minister Jawaharlal Nehru to announce the formation of the first linguistic state, Andhra State, which was officially formed on October 1, 1953. This event set a precedent for the reorganization of all Indian states along linguistic lines through the States Reorganisation Act of 1956.
Step 3: Final Answer:
The name of the activist who went on a fast for the creation of linguistic states was Potti Sreeramulu.