The document traces the history and development of radio technology from early experiments in the late 19th century to its rise as a mass communication medium in the mid-20th century. Some key developments and events include Thomas Edison's early experiments in the 1870s, David Hughes transmitting radio waves in 1878, the invention of the coherer detector by Calzecchi-Onesti in 1884, and radio becoming a central part of American life and culture during the Golden Age of Radio from 1935-1950. Today, radio remains popular for listening to music and news while driving.

1. Radio