The Arc is the national organization of and for people with mental retardation and related developmental disabilities and their families. It is devoted to promoting and improving supports and services for people with mental retardation and their families. The association also fosters research and education regarding the prevention of mental retardation in infants and young children. The Arc was founded in 1950 by a small group of parents and other concerned individuals. At that time, little was known about the condition of mental retardation or its causes, and there were virtually no programs and activities in communities to assist in the development and care of children and adults with mental retardation and to help support families. The Arc is a grassroots organization with more than 140,000 members, who are affiliated through more than 1,000 state and local chapters across the nation, including this chapter in Downey, Calif.