AT&T began experimenting with a video telephone as early as 1927. Its famous Bell Laboratories developed the 1956 "Picture-Phone" prototype seen in the upper left. It transmitted pictures in trials from New York to Los Angeles, sending out one b&w picture every two seconds. It required a line for video reception, one for video transmission, and one for audio. At the lower left is a "picture phone" prototype at Bell Labs circa 1961. The camera is the circle to the left of the screen.
Right: The U.S. Army Signal Corps at Fort Monmouth, N.J. developed this "television phone booth" in 1951.