The Decoding Dyslexia movement began in 2011 when twelve New Jersey parents took the same train ride home from a learning disabilities luncheon in New York City and discovered they all had the same story of struggles to get services for their children in the public school system. They formed a grassroots movement called Decoding Dyslexia New Jersey and the mission was to raise dyslexia awareness in their state, to provide resources to families, and to implement policy change. The had success and created a guide for other states to form their own chapter.
There is no National Decoding Dyslexia. Each chapter is run as an independent organization so contact your state chapter for more information about what they are doing and how they are structured. Find a link to each of the chapters at the Decoding Dyslexia national web site.
Here is a video of the how Decoding Dyslexia all started.