Danny Howard, who plays for Sydney club Wentworthville in the NSW Cup, scored three of his side's eight tries in Jacksonville.
It confirmed the Hawks' place at the tournament in Australia and New Zealand following their success at the 2013 World Cup in which they were surprise quarter-finalists before going down 62-0 to the Kangaroos.
Howard and brother Stephen were born in Los Angeles before their family moved back to Canberra when they were young.