In 1915, before commercial broadcasting existed, David Sarnoff, an assistant traffic manager at the Marconi Wireless Telegraph Company of America, proposed to build and sell a “radio music box,” and wrote, “I have in mind a plan of development that would make radio a household utility.…”

When a new outfit called Radio Corporation of America took over Marconi, just after World War I, it acquired Sarnoff as an asset. He pursued his idea—and saw it yield more than $80 million in sales by the mid-1920s. In 1926 he led RCA into the new field of radio networks, forming the National Broadcasting Company. He was named president of RCA in 1930.

He soon turned his attention to television, and RCA’s NBC network became hugely popular. Sarnoff could rightly boast that he had introduced both radio and television as mass media.

—T.A.H.