This document summarizes the history of computers from the 1940s to the 1960s. It describes several important figures who contributed to early computer development including Alan Turing, John Vincent Atanasoff, Clifford Berry, Konrad Zuse, John von Neumann, Howard Aiken, Grace Hopper, Claude Shannon, and Douglas Engelbart. It provides details on some of the earliest computers such as the Z3, the Atanasoff–Berry Computer, the Harvard Mark I, Colossus, and ENIAC. It also discusses the development of programming languages, compilers, transistors, and human-computer interaction innovations like the computer mouse.