The Americans with Disabilities Act (ADA) was first passed in 1990. Twenty years later, the US Department of Justice released an update called the 2010 ADA Standards for Accessible Design. These standards cover the design of physical spaces and have been interpreted to include web locations as well, so it can be difficult for the would-be accessible website designer to use them.
Hey Casey, this is one of the areas where things get a little weird because the W3 doesn’t actually have any say over the ADA guidelines, it is more than the ADA guidelines adopted the WCAG 2.0 guidelines as just that, a guideline to help. As far as I know, the tool you’ve linked to hasn’t been used in any judgements I’m aware of. Usually when it comes down to making a decision on if something is/isn’t compliant they have people use the actual PAWS tools and show what elements do/don’t work as intended or are otherwise inaccessible. Hope this helps!

For most people, the Americans with Disabilities Act (ADA) conjures up pictures of physical accommodations such as wheelchair ramps near building entrances, handicapped parking spaces, and the use of braille writing on signs and placards. These measures have been tremendously valuable in helping the 56.7 million Americans with a disability function and thrive within society.
I know there may have been concerns that the ADA may be too vague or too costly, or may lead endlessly to litigation. But I want to reassure you right now that my administration and the United States Congress have carefully crafted this Act. We've all been determined to ensure that it gives flexibility, particularly in terms of the timetable of implementation; and we've been committed to containing the costs that may be incurred.... Let the shameful wall of exclusion finally come tumbling down.[41]
This title requires telephone and Internet companies to provide a nationwide system of interstate and intrastate telecommunications relay services that allows individuals with hearing and speech disabilities to communicate over the telephone. This title also requires closed captioning of federally funded public service announcements.  This title is regulated by the Federal Communication Commission. 
HTML tags – specific instructions understood by a web browser or screen reader. One type of HTML tag, called an “alt” tag (short for “alternative text”), is used to provide brief text descriptions of images that screen readers can understand and speak. Another type of HTML tag, called a “longdesc” tag (short for “long description”), is used to provide long text descriptions that can be spoken by screen readers.
This is an article that most other website developers probably don’t want you to read. The reason is that most other web designers basically like to think of themselves as all-powerful wizards with magical powers. And they use complex technical jargon and terminology to intimidate and mystify their clients into thinking that what they do is more complex than it is.
This title outlines the administrative processes to be followed, including requirements for self-evaluation and planning; requirements for making reasonable modifications to policies, practices, and procedures where necessary to avoid discrimination; architectural barriers to be identified; and the need for effective communication with people with hearing, vision and speech disabilities. This title is regulated and enforced by the U.S. Department of Justice.
Camacho is a blind resident of Brooklyn, NY. He is currently making headline news for taking 50 colleges to court under ADA lawsuits. Camacho filed lawsuits regarding website accessibility for all 50 of the colleges. The plaintiff uses a screen-reader but experienced a barrier when trying to access information. The majority of colleges being taken to court are private, including Cornell and Vanderbilt to name a couple.
While the U.S. Department of Labor's (DOL) Office of Disability Employment Policy (ODEP) does not enforce the ADA, it does offer publications and other technical assistance on the basic requirements of the law, including covered employers’ obligation to provide reasonable accommodations to qualified job applicants and employees with disabilities. For a quick overview of the ADA read “The Americans with Disabilities Act: A Brief Overview.”

“The idea of equal access, equal opportunity has sort of evolved in its application from brick and mortar to eCommerce. At first, many companies were worried about the desktop experience. Now, the concern extends to both smart phones and devices.  Wherever a consumer accesses your content – whether it be directly through the web or an app – you need to be concerned about accessibility.”
Once you have been hired and started work, your employer cannot require that you take a medical examination or ask questions about your disability unless they are related to your job and necessary for the conduct of your employer's business. Your employer may conduct voluntary medical examinations that are part of an employee health program, and may provide medical information required by State workers' compensation laws to the agencies that administer such laws.