This book provides a history of the efforts of the US National Science Foundation to broaden participation in computing. The book briefly discusses the early history of the NSF's involvement with education and workforce issues. It then turns to two programs outside the computing directorate (the ADVANCE program and the Program on Women and Girls) that set the stage for three programs in the NSF computing directorate on broadening participation: the IT Workforce Program, the Broadening Participation in Computing program, and the Computing Education for the 21st Century program. The work looks at NSF-funded research and NSF-funded interventions both to increase the number of women, underrepresented minorities (African Americans, Hispanics, and American Indians) and people with disabilities, and to increase the number of public schools offering rigorous instruction in computing. Other organizations such as the ACM, the Computer Science Teachers Association, and Code.org are also covered.The years covered are primarily 1980 to the present.