The result keeps Scotland's prospects very much alive in Group D as they seek to qualify for the knockout stage for the first time in a major finals.
Clarke made a big call when playing Gilmour from the start on a night when Scotland had to gain at least a point.
They managed to do this and could even have snatched a famous win at Wembley. Gilmour, who only turned 20 last week, was at the heart of everything Scotland did well until being substituted with 14 minutes left.
The Chelsea midfielder earned the man of the match award, relayed across the Wembley Tannoy at the end. But Clarke felt O’Donnell had put in the performance of the night at right wing-back.
The Motherwell player might well have opened the scoring in the first half but was denied by a one-handed stop by England goalkeeper Jordan Pickford.
He coped well with the challenge of keeping Raheem Sterling quiet and also England’s attacking left back Luke Shaw, who was some believed was picked with the intention of trying to exploit Scotland’s supposed weakness on their right. O'Donnell also impressed when Phil Fodenwas switched to his flank.
Asked about Gilmour’s performance, Clarke answered: “I thought Stephen O’Donnell was exceptional,” he said. "And Billy was just behind him. It was nice for Billy to get that start – big platform, big stage, big player. We’ve said for a long time he was part of the future of Scottish football. We know what we’ve got in the camp and we will try to manage him properly and keep a lid on things. Performances like that will do him no harm whatsoever.”
He harboured no fears about giving Gilmour his full debut on such an important night.
“I don’t think there is any risk when you have somebody of Billy Gilmour’s talent,” he said. “When you put him on the pitch you expect him to do what he did. He held the ball for us and allowed us to play through the midfield. I didn’t think it was a risk for the balance of the rest of the team. We were ready to support Billy in his role and I think we did that.”
Clarke denied that the criticism following Monday’s 2-0 defeat to Czech Republic was a particularly motivating factor.
“Nope,” he said. “The motivating factor was to get something out of the game so we could go into the last game with a chance of qualifying out of the group.”
It was not just the point that pleased him, but the fact Scotland had secured it by playing some excellent football. England were booed off at the end by their fans.
“We played well,” said Clarke. “We had to be solid defensively when England had the ball to stop them creating the chances they will always create in the game. That side was pleasing. But yes, it was pleasing that we could play from the back, play through the midfield, and at times we played a lot of good football. That was nice to see.
“Getting Kieran (Tierney) back into the back three, and Scott (McTominay), gives us the platform to build from the back and play football from the back,” he said.
“Billy and Callum (McGregor) in midfield are both good footballers. We knew we couldn’t come here and just in and defend for 95 minutes or whatever the game was going to be. We knew we had the ball we had to try and take care of it and create our own chances and that’s what we managed to do.”