This document provides an overview of the history and evolution of instructional technology used in K-12 classrooms from the 19th century to present day. It discusses early technologies like chalkboards, the visual instruction movement using films and slides in the early 20th century, the introduction of radio and television in the 1920s-1950s, and computers starting in the 1950s. The document then covers innovations and uses of these technologies over time, as well as standards for 21st century skills, digital literacy, and the role of technology in education.