First-half tries from stand-in captain George Ford, Billy Vunipola and Luke Cowan-Dickie gave England a 19-0 lead at the break before Joe Cokanasiga secured the bonus point early in the second half.
Ruaridh McConnochie and Lewis Ludlam then scored their maiden Test tries before Eagles flanker John Quill was sent off 10 minutes from time for an illegal shoulder charge on replacement back Owen Farrell.
There was still time for Cokanasiga to grab his second try and England’s seventh before Bryce Campbell ensured the USA avoided the embarrassment of being ‘nilled’ with a try after 80 minutes were up.
England, the 2003 world champions, made 10 changes to the side that beat Tonga 35-3 in their Pool C opener in Sapporo last weekend for what was the USA’s first match of this tournament.
Under the closed roof of the Kobe Misaki Stadium, the Eagles suffered an early setback when, after the opening scrum, 19-year-old prop David Ainu’u limped off injured in the third minute.
And three minutes later England had their first try.
Number eight Vunipola, making his 11th consecutive Test start, ran the ball from deep before Ford, leading England in place of the benched Farrell, spotted a gap in the poorly aligned defence and ran in a try between the posts which he converted.
England, however, again conceded several early penalties before the forwards provided their second try.
Ford, declining a kickable penalty, booted the ball deep for an attacking line-out.
The ensuing rolling maul saw Vunipola driven over in the 25th minute, with Ford converting.
England’s third try arrived in similar fashion eight minutes later, the Eagles again powerless to resist a rolling maul from a penalty line-out, with hooker Cowan-Dickie scoring his second try in two matches.
Ford’s conversion hit the post but England were still 19-0 in front.
They could have had a bonus point on the stroke of half-time only for centre Jonathan Joseph to knock on in sight of the line.
Early in the second half, Ford carelessly failed to set up another attacking line-out when he carelessly kicked a close-range penalty dead.
That mistake prompted the Eagles’ best spell of the match only for England to force a ruck penalty.
Cowan-Dickie’s bonus-point try against Tonga did not arrive until four minutes from time, but England had no such problems in this match.
A quickly taken line-out caught the Eagles napping and, after a fine pass from flanker Tom Curry, Joseph broke clear only to be hauled down a yard short before Ford found Cokanasiga, with the Fiji-born flyer forcing his way over.
Ford again missed the conversion but England were 24-0 ahead.
Eddie Jones, the England coach, then sent on several senior players, including Farrell and scrum-half Ben Youngs.
By coming off the bench, Youngs joined starting prop Dan Cole in winning his 91st England cap as the pair went into joint third place on the national list alongside 2003 hero Jonny Wilkinson.
England crossed the Eagles’ line again in the 58th minute when Joseph found McConnochie.
And against a tiring defence, Ludlam joined McConnochie in scoring a maiden Test try in the 67th minute.
In a tournament where officials have been criticised for failing to implement World Rugby’s directive on dangerous tackles, Australian referee Nic Berry, after consulting the television match official, dismissed Quill for a late hit on Farrell.
The USA next play France in Fukuoka on October 2, while England facing Argentina in Tokyo on October 5. (AFP)