According to Mass Moments, a web site produced by the Massachusetts Foundation for the Humanities: "On this date in 1951... a program was transmitted live from coast-to-coast for the first time ever. President Harry Truman's opening speech at the Japanese Peace Conference in San Francisco was broadcast... Both the content and the technology were significant. The Peace Conference would formalize the end of hostilities with Japan, opening the door for Japan's economic recovery, while the broadcast initiated a new era in telecommunications.
"The linking of the country in a simultaneous broadcast evoked the day in 1869 when the Golden Spike was driven to mark the completion of the first transcontinental railroad. Only this time the new connections were carrying words and pictures, not passengers and freight.
"As soon as World War II was over, the number of TV stations, almost all located in cities, began to grow exponentially. In 1946 six stations were broadcasting to about 20,000 households; by 1950, 98 stations were reaching approximately 7,000,000 households — nearly one in every ten...
"But wiring the entire nation was an expensive proposition. In 1948 AT&T invested $40 million in an experiment. The company used microwave radio technology to transmit a television signal from San Francisco to Chicago, and then existing coaxial cables to carry the signal from Chicago to the East Coast. This made it possible for people in over 50 cities across the country to view the same programming at the same time.
"The opening session of the Japanese Peace Convention in San Francisco represented the first trial for the experimental system, and it was a success. Eighty-seven stations all over the U.S. received and broadcast Truman's speech.
"Regular network shows soon followed. Within a month, I Love Lucy debuted on CBS..."