Profile America -- Thursday, March 4th. FM radio as we know it began this week in 1941. That's when the first commercial FM station went on the air -- W47NV in Nashville. FM -- standing for frequency modulation -- was first proposed in a scientific paper written by Edwin Armstrong in 1922. By 1934, he demonstrated how FM was unaffected by static, unlike all the radio stations then on the air, which used AM or amplitude modulation. Critics said the idea was impractical. World War II interrupted the advance of FM broadcasting, which slowly began to gain popularity in the 1950s. Today, there are nearly 11,000 radio stations around the nation -- close to six-out- of-10 of them operating on the FM band. Profile America is in its 13th year as a public service of the U.S. Census Bureau.

Sources: Kane's Famous First Facts, 6299
www.history.com
Statistical Abstract of the United States 2010, t. 1095
http://www.census.gov/compendia/statab/2010edition.html