The Red Devils seized control of the friendly with three goals in ten second-half minutes as they launched their USA exhibition tour in rousing style.
Michael Owen and Park Ji-Sung also scored for United, who started just four players from the side that lined up for the UEFA Champions League final against Barcelona in May.
Young made his United debut after joining the Red Devils from Aston Villa last month, while Wayne Rooney came on for the second half.
Carrick the creator
But it was Michael Carrick who caught the eye, creating two goals. The supply line on the night, he set up Owen and Macheda with clever passes, the first allowing Owen to fire a low shot beyond the New England goalkeeper.
Macheda scored the second shortly after, and added a third in the 61st minute, converting a pass from Rafael that fizzed across the goalmouth.
Gabriel Obertan did all the hard work in setting up the fourth United goal, tying New England defender Zak Boggs in knots with some nifty footwork, before passing to Ryan Giggs, who fed Park for a late chip over the New England keeper.
Kenny Mansally scored the lone goal for New England, who are in last place in the Major League Soccer Eastern Conference standings.