Russell Slade admits he has "never seen anything like it" as the O's reached Wembley following an extraordinary play-off win over Peterborough United.
Orient defeated the Posh 2-1 and 3-2 on aggregate which sparked an incredible pitch invasion at Brisbane Road.
There was an unforgettable atmosphere in East London as the fans celebrated while their heroes enjoyed the party in the directors' box.
Slade said: "I'm a very proud man obviously. I thought the players were an absolute inspiration and the crowd were an inspiration tonight. I've never seen anything like that at this place in the four and a bit years I've been here.
"The Peterborough fans were outstanding but our fans were extraordinary tonight. They got behind the boys from the first minute and it was like a new football club being reborn today."
Slade insists tonight's triumph can give them the belief to go all the way and win a place in the Championship on Sunday, May 25.
The O's boss said: "There was a real belief around the stadium and a real togetherness which was what we required. After tonight, we realise if we're all like that together we can achieve a lot of things.
"It was amazing and a fantastic night for the football club. I'm sure it will live on in the history of many people's minds. We've achieved something quite remarkable already by getting to Wembley but there is still so much more work to do now.
"We're not just going there to make the numbers up. We're going there to get to the next level if we possibly can."