He will retire at the end of the season.
Ferguson: "I decided at Christmas. Cathy's sister died. She had lost her best friend and she has been isolated. For 47 years she has been the leader of the family. She has made a lot of sacrifices for me. It was difficult to keep it a secret. Sometimes we nearly blurted it out to the family and we told our sons in March but my brother didn't know until Tuesday. I wanted to tell the players first and also my staff. Unfortunately there were rumours going around on Tuesday so we started to speed it up a bit."
Ryan Giggs, veteran Manchester United midfielder: "Sir Alex just said play the game and not the occasion. He wanted to win the game, wanted it to be an entertaining game and for us to do the things which he has wanted us to as a manager. The memories of him that stick out are when I was younger. When I was 13 playing for Salford Boys and looking to the sidelines and there was Sir Alex Ferguson watching."
Nemanja Vidic, Manchester United captain: "It will be strange not to see him in the dressing room. This is a big club and will always be a big club but it is sad after so many years, without him is going to be sad. Even on the last day he wanted to win the game. He told us this is the mentality you have to have when I go, always fight, always want to win."
Michael Carrick, Manchester United midfielder: "It's been an emotional day for everyone. It was a strange feeling and it's been like that all week. It was a special, special day. Even in the changing room he tried to keep it as normal as possible but in the back of your mind you were thinking this is the last one. With the reception he got, it was amazing."
Robin van Persie, Manchester United striker: "It's an unbelievable day but a sad one as well. I had the honour to work with him for one year and it's been an unbelievable year. He's made such an impact on me. He may be the greatest manager ever and he's such a nice person."
Paul Scholes, retiring Manchester United midfielder: "It's been a good day. We've won the game, that's all that matters. We'll celebrate tonight and hopefully in more years there will be more trophies for these players. Today it was just nice to get through the game. I thought Sir Alex handled it well, he spoke really well and he has done a fantastic job here."
Michael Laudrup, Swansea City manager: "It is a special day. It is one thing that a manager in a big club stops, but this is a lifetime not a small era. It is incredible. I have a lot of respect for Sir Alex to have so many years in the same club, so unique. It is a lifetime."