Bill Rasmussen -- the founder of ESPN -- has died at 93 years old from the effects of Parkinson's disease, the network announced Tuesday.

Rasmussen was credited with creating the first 24-hour television network when he launched the Entertainment and Sports Programming Network with his son, Scott, in 1979 ... which would change the medium forever.

Rasmussen was the network's inaugural president and CEO ... and was able to form relationships with sports leagues, investors and cable operators to set the network up for years to come.

ESPN chairman Jimmy Pitaro remembered Rasmussen as a "remarkable man" and a "visionary and an innovator."

"Quite simply, none of us would be here today if it wasn't for Bill's passion and all the hard work and entrepreneurial spirit he put into building ESPN in the late 1970s -- key aspects of our company culture that still carry on to this day."

ESPN legend Chris Berman -- who joined the network weeks after it launched -- also shared a tribute to "our George Washington."

"He was such a grateful person and every sports fan can be grateful for Bill. He wasn't a glass half-full guy; his glass was always overflowing with optimism. He greeted everyone with a smile and we can all smile knowing Bill's legacy."