The Reber Radio Telescope at Green Bank Observatory is a landmark in the history of radio astronomy. Built in 1937 by Grote Reber in his backyard in Wheaton, Illinois, it was the first purpose-built parabolic radio telescope, following Karl Jansky’s earlier detection of radio waves from the Milky Way. At a time when Reber was essentially the world’s only radio astronomer, he used the telescope for pioneering sky surveys that helped establish the field and identified important radio sources such as Cassiopeia A and Cygnus X-1. Its design became a prototype for larger postwar dish telescopes, and it was later moved through several institutions before reaching Green Bank.