The Department has assembled an official online version of the 2010 Standards to bring together the information in one easy-to-access location. It provides the scoping and technical requirements for new construction and alterations resulting from the adoption of revised 2010 Standards in the final rules for Title II (28 CFR part 35) and Title III (28 CFR part 36).
The Americans with Disabilities Act (ADA) was developed in 1990 and is meant to ensure that people with disabilities have the same opportunities as anyone else. This means any businesses that serve the public must make sure their building accommodates people with disabilities of various kinds. And now that the internet is so widely used, ADA compliance also applies to websites and even mobile apps. Basically, this means that your website needs to be accessible to people who have disabilities that affect their hearing, vision or physical capacities.
This is the reason why I think web design firms have to position themselves as solution providers and not just web guys/gals. A client doesn't need a website, they need sales. The website is just part of that solution but it's not the solution and unlike web design, service like email marketing automation, SEO, and PPC requires an experienced professional.
So, without a clear set of accessibility regulations to comply with, how can you tell if your website is compliant? The best measure available is the aforementioned WCAG 2.0 Level AA guidelines. WCAG standards have been the guiding accessibility principle in the European Union and other countries since 1999, with the most recent update taking effect in Spring of 2018. While WCAG is a set of recommended actions rather than enforceable legislation, it forms the backbone of many online accessibility laws around the world and offers a strong model for any American organization striving to provide equal access for all users.