The legislation prohibiting discrimination on the basis of disability was signed into law on July 26th twenty years ago.
The NISE Net has worked to create products that meet the needs of a diverse group of visitors, including people with and without disabilities, and through that work has developed universal design guidelines for both exhibits and public programs. You can find the guides in the Tools and Guides section of the NISE Net catalog (/search/product_category/professional-development-27):
For more information on the Network's efforts to reach a diverse audience with regard to geography, dis/ability, gender, race/ethnicity, language, and income, check out the Inclusive Audiences work group page.