This short history of nuclear regulation provides a brief over-view of the most significant events in the U.S. Nuclear Regulatory Commission's past. Space limitations prevent discussion of all the important occurrences, and even the subjects that are included cannot be covered in full detail. The first chapter of this account is taken from George T. Mazuzan and J. Samuel Walker, Controlling the Atom: The Beginnings of Nuclear Regulation, 1946-1962 (University of California Press, Berkeley, CA, 1984). The second chapter is largely based on J. Samuel Walker, Containing the Atom: Nuclear Regulation in a Changing Environment, 1963-1971 (University of California Press, Berkeley, CA, 1992). The third chapter is adopted in significant part from J. Samuel Walker, Three Mile Island: A Nuclear Crisis in Historical Perspective (University of California Press, Berkeley, CA, 2004). The findings and conclusions on events that occurred after 1979 should be regarded as preliminary and tentative; they are not based on extensive research in primary sources.