This document summarizes an accessibility 101 presentation given to a UX meetup group. It discusses the evolution of accessibility laws and guidelines over time, including Section 508, ADA, WCAG, and WAI-ARIA. The four principles of WCAG 2.0 are explained: perceivable, operable, understandable, and robust. The document also provides details on several proposed success criteria for WCAG 2.1, including resizing content, graphics contrast, and interruptions. Feedback from WebAIM on some of the proposed WCAG 2.1 changes is also summarized.