During the night hours of January 27, 1917, eighteen-year-old Willis Porter Corwin received and re-transmitted three Morse Code messages in Jefferson City, completing the first successful one-way transcontinental relay of formal message traffic in American radio history. Conducted as an experiment by pioneer amateur radio operators, the messages originated with citizens in Los Angeles, were sent to a station in Denver, relayed to Corwin, passed on to a station in Albany, New York, and then forwarded to Hartford, Connecticut. Ten days later, he repeated the experiment in more dramatic fashion by conducting the first successful two-way transcontinental relay, in which a message started from the East Coast, was relayed to the West Coast, and an answer was received back on the East Coast within eighty minutes. Jefferson City's first-known amateur wireless operator, recognized by the call sign 9ABD, Corwin built his spark-gap transmitter, power supply, and antenna entirely by hand, with his radio shack in an enclosure at the base of a wooden tower supporting his Marconi-style antenna behind his parents' residence at 117 E. McCarty Street. The first man from Jefferson City to enlist in World War I, he served with the United States Naval Reserves as Chief Electrician (Radio) in France and as a wireless operator aboard the troop ship taking him to Europe. After the war, Corwin built and installed Jefferson City's first commercial AM broadcast station, WOS, in the dome of the State Capitol for the Missouri Department of Agriculture. He later helped construct radio station KSD in St. Louis for the St. Louis Post-Dispatch, where he did pioneering work on wire-photo transmission years before it became a reality. Corwin died at age sixty on January 27, 1959, exactly forty-two years after the transcontinental record, and was buried in Jefferson City National Cemetery, nine blocks east of this site.