The first computer mouse was conceived in the early 1960s by Douglas Engelbart. The mouse was just a tiny piece of a much larger project, started in 1962, aimed at augmenting human intellect.
The original mouse had the cord in the front, but they quickly moved it to the back end to get it out of the way. It was a simple mechanical device with two perpendicularly mounted discs on the bottom.
The first production workstation and mouse were made in 1967. The mouse, as well as other advanced technologies, were demonstrated by Douglas Engelbart in the famous demonstration of experimental computer technologies on December 9th, 1968.