Commenting on his selection Henry said, " I am delighted to be named in the squad and am looking forward to the weeks ahead and I will be doing my best to get an opportunity to play some rugby."
England - minus the players from the Aviva Premiership final the previous day - are taking on the Barbarians at Twickenham Stadium on May 26 before playing a CONSUR XV, representing the South American nations, in Montevideo, Uruguay, on June 2, and then Tests against Argentina in Salta (June 8) and Buenos Aires (June 15).
Captained by Northampton Saints' Tom Wood, the group includes five players who are 21 or under, the youngest of whom is London Wasps No.8 Billy Vunipola, who represented England Under 20s last year.
England Head Coach Stuart Lancaster said: "We're really looking forward to this tour and we've selected a young and exciting side which I'm sure will do the country proud in a tough series of matches.
"The key principles in selection were threefold: first and foremost to win the games but also to develop strength in depth and more options in certain positions, and to give one or two players a physical and mental break.
"We feel we've got the balance right and have given places to a number of players who have shone in the Aviva Premiership this season, one or two who have been on the fringes for a while, and several players who have been involved over the last year or so. This is everyone's chance to step up.
"Tom Wood will captain the side and I am sure he will do a fantastic job, as he has the respect of all the players and management and we are looking forward to other leaders developing in the absence of some senior players.
"A few are being rested after a hard campaign but they will, of course, be considered by the British & Irish Lions should they be required."
Players rested include Chris Robshaw, Danny Care (both Harlequins), Toby Flood (Leicester Tigers), Brad Barritt and Chris Ashton (both Saracens).
Anthony Allen (Leicester Tigers) and James Haskell (London Wasps) were not considered on medical grounds.
Dave Attwood (Bath Rugby, 2 caps)
Rob Buchanan (Harlequins, uncapped)
Calum Clark (Northampton Saints, uncapped)
Alex Corbisiero (London Irish, 18 caps)
Paul Doran Jones (Northampton Saints, 4 caps)
Tom Johnson (Exeter Chiefs, 5 caps)
Matt Kvesic (Worcester Warriors, uncapped)
Joe Launchbury (London Wasps, 9 caps)
Courtney Lawes (Northampton Saints, 20 caps)
Joe Marler (Harlequins, 10 caps)
Ben Morgan (Gloucester Rugby, 10 caps)
David Paice (London Irish, 6 caps)
Ed Slater (Leicester Tigers, uncapped)
Henry Thomas (Sale Sharks, uncapped)
Billy Vunipola (London Wasps, uncapped)
Rob Webber (Bath Rugby, 3 caps)
David Wilson (Bath Rugby, 26 caps)
Tom Wood (Northampton Saints, captain, 18 caps)
Mike Brown (Harlequins, 16 caps)
Freddie Burns (Gloucester Rugby, 1 cap)
Lee Dickson (Northampton Saints, 7 caps)
Kyle Eastmond (Bath Rugby, uncapped)
Ben Foden (Northampton Saints, 30 caps)
Alex Goode (Saracens, 11 caps)
Jonathan Joseph (London Irish, 4 caps)
Jonny May (Gloucester Rugby, uncapped)
David Strettle (Saracens, 13 caps)
Joel Tomkins (Saracens, uncapped)
Billy Twelvetrees (Gloucester Rugby, 4 caps)
Christian Wade (London Wasps, uncapped)
Richard Wigglesworth (Saracens, 12 caps)
Marland Yarde (London Irish, uncapped)