Step 1: Understanding the Concept:
The question asks to identify the founder of the All India Harijan Sevak Sangh, a significant social reform organization.
Step 2: Detailed Explanation:
The All India Harijan Sevak Sangh was founded by Mahatma Gandhi on September 30, 1932. He established the organization following his fast at Yerwada Jail in Pune, which led to the Poona Pact. The primary objective of the Sangh was to eradicate untouchability from Indian society and work for the social, economic, and cultural upliftment of the 'Harijans' (a term coined by Gandhi for the so-called 'untouchables', meaning 'children of God').
Step 3: Final Answer:
Mahatma Gandhi established the All India Harijan Sevak Sangh in 1932.