Distance learning has considerable history in American education.
For decades, correspondence courses have linked sources of instruction to remote individual learners through exchange of printed materials by mail. Also, radio and television have been used for a variety of distance learning schemes involving virtually all disciplines. Within science education, an early example of distance learning involved delivery of primary instruction for high school physics in the form of 16mm films which were mailed to be shown daily in classrooms. Later, but before communications satellites were highly developed, another distance learning project had televised science instruction beamed to classrooms from a high-flying airplane. Such early forms of distance learning were limited by a low degree of interaction between learners and sources of instruction.