Complex sentence: The idea grew and by March 1956 the Parks Board created an Arena Committee, which it named the "Essex Memorial Arena Campaign Committee", and appointed members from the Essex Rotary Club, the Legion (Branch 201), and the Kinsmen Club of Essex.
Split into simpler sentences: The idea grew and by March 1956 the Parks Board created an "Arena committee". The "Essex Memorial Arena Campaign Committee" was made up of people from the Essex Rotary Club, the Legion (Branch 201), and the Kinsmen Club of Essex.