Short told the club's official website: "Probably like every other good Sunderland football club fan, I'm ecstatic and if I had to pick one word, it would be 'relieved', relief that two months of fear and nervousness is over.
"This club has a lot of reasons to stay up. We have got a lot of good plans for the future and relegation would have been horrible, so I'm relieved and happy."
Short also stressed that chairman Niall Quinn will run the football side of things at Sunderland while he remains very much in the shadows.
The American businessman said: "Niall runs the club. Niall is a very smart footballer, very smart about the Premier League and is a wonderful chairman of the club who knows more about football than I ever will, so I will be in the background and Niall will be running the show.
"I will be involved in things like finance. With me coming in, you get all of these other good ingredients that are already in place at the club and can add to that a streamlined decision-making process, a streamlined board and with some financial ability to make some moves - and we think that is the missing piece that this club has needed."