Electro-Magnetic Propulsion

Yah I remember that.

It was based on the fact that it had the greatest potential (in theory) to obtaining speeds closest to the speed of light, and required the least amount of fuel and weight. The math stated that it would typically take a year to get it up to speed but for the long haul (such as interstellar travel it would outstrip any other technology theorized at the time.

There actually has been some successful tests done by some countries, however, I think the potential energy transfer was extremely low