Answer:
Due to ignorance of government.
Explanation:
It took very long time for the country to acknowledge and protect the rights of the disabled because the leaders of the country can't take it seriously and did not know the difficulties and problems of a disabled people. The other reason for its taking long time is the participation and interest of parents of disabled people. When more number of parents comes for the rights, it put pressure on the government and the government then passed the disabilities act. At last, The President George H.W. Bush passed the Americans with Disabilities Act (ADA) on July 26, 1990.