WWVB: A Half Century of Delivering Accurate Frequency and Time by Radio

In commemoration of its 50th anniversary of broadcasting from Fort Collins, Colorado, this paper provides a history of National Institute of Standards and Technology (NIST) radio station WWVB. The narrative describes the evolution of the station, from its origins as a source of standard frequency, to its current role as the source of time-of-day synchronization for many millions of radio controlled clocks.