Radio was popularized in the late 20’s early 30’s. The broadcast happened on Oct 31st 1938.

12M listeners – surveys found that 1 in 12 thought it was true – 1M people

“a “War of the Worlds” reenactment happened in the mountains of Quito, Ecuador, 1949.”

the Chase & Sanborn hour ran alongside the Mercury Theatre at the same time – this show was much more popular which is why most people missed the introduction stating it was fake. They only tuned in after Chase and Sanborn brought on an unpopular singer.