England scored 17 tries in their win against the USA, with a hat-trick coming from captain Alex Day, two from Warriors' Howard, two from Henry Purdy, two from David Sisi, two from Ross Moriarty, two from Joel Conlon, two from Tom Stephenson and a try-apiece from Ollie Devoto and Tom Smallbone. Fly half Will Hooley kicked 22 points while Devoto also added one conversion.
England started strongly and were ahead with the first play of the game after a strong burst forward from full back Devoto freed up space for Purdy to dive over in the corner.
The second came just three minutes later in the same corner - captain Day picking up the ball in space and showing good strength to go over for his first England Under 20 try.
England's third try after eight minutes was touched down at the back of a scrum by Sisi and the fourth came minutes later from Day, who went over for his second.
The fifth came through flanker Moriarty who showed good strength to score and the sixth came from fellow back rower Joel Conlon, who went over in the corner.
The seventh and eighth tries came just before the break, first Devoto and then Howard going over to give England a 48-0 lead at half-time.
Conlon picked a hole in the USA defence early in the second half to make it 53-0 before Howard ran through for his second, with Day then completing his hat-trick after peeling off the back of a scrum to score.
At 69-0 up England continued to push and were rewarded when Moriarty went over for his second. Stephenson then scored his first try before Purdy claimed his second with 59 minutes played.
Sisi scored his second from the back of a scrum before Smallbone burrowed over for his first England U20 try to bring up the ton and Stephenson rounded off the scoring in the 74th minute to make it 109-0, a record in the IRB Junior World Championship.
Captain Day said: "We're obviously delighted to get the win. The scoreline doesn't reflect the physical challenge USA gave us - we wish them well in their next game, we've been sharing a hotel with them for the past couple of weeks and they're a really good group.
"From our point of view though we're just over the moon to progress in the competition. Playing New Zealand in the semis will be a real challenge but it's one we're looking forward to. If you want to win the competition you have to play the best teams.
"I was so proud to lead the guys out - it was a pretty special feeling, but to score a few tries and to get the record win means a lot. We made a few changes for this game but it just goes to show the strength in depth we've got."
Points: Purdy 2T, Day 3T, Sisi 2T, Moriarty 2T Conlon 2T, Devoto 1T, Howard 2T, Stephenson 2T, Smallbone 1T; Hooley 11C, Devoto 1C.
England Under 20 XV against USA
15. Ollie Devoto (Bath Rugby)
14. Ben Howard (Worcester Warriors)
13. Tom Stephenson (Northampton Saints)
12. Harry Sloan (Harlequins)
11. Henry Purdy (Leicester Tigers)
10. Will Hooley (Northampton Saints)
9. Alex Day (Northampton Saints, captain)
1. Alec Hepburn (London Wasps)
2. Scott Spurling (Saracens)
3. Tom Smallbone (London Irish)
4. Harry Wells (Leicester Tigers)
5. Tom Price (Leicester Tigers)
6. Ross Moriarty (Gloucester Rugby)
7. Joel Conlon (Exeter Chiefs)
8. David Sisi (Bath Rugby)
16. Nathan Morris (London Wasps) on for Harry Sloan 50 mins
17. Danny Hobbs-Awoyemi (Northampton Saints) on for Alec Hepburn 66 mins
18. Scott Wilson (Newcastle Falcons) on for Tom Smallbone 68 mins
19. Dominic Barrow (Leeds Carnegie) on for Ross Moriarty 58 mins
20. Jack Clifford (Harlequins) on for David Sisi 71 mins
21. Callum Braley (Bristol Rugby)
22. Henry Slade (Exeter Chiefs)
23. Jack Nowell (Exeter Chiefs)