The article is intended to introduce the readers to the concept and background of Web accessibility in the United States. I will first discuss different definitions of Web accessibility. The beneficiaries of accessible Web or the sufferers from inaccessible Web will be discussed based on the type of disability. The importance of Web accessibility will be introduced from the perspectives of ethical, demographic, legal, and financial importance. Web accessibility related standards and legislations will be discussed in great detail. Previous research on evaluating Web accessibility will be presented. Lastly, a system for automated Web accessibility transformation will be introduced as an alternative approach for enhancing Web accessibility.