Leading Participation theorist Frederick Jackson Turner went Self_motion deeper , arguing Quarreling that the frontier was the defining process of American civilization : `` The frontier , '' he asserted Statement , `` promoted Cause_change_of_position_on_a_scale the formation Coming_to_be of a composite nationality for the American people . ''

by august 1945 , the allies ' manhattan project had produced Manufacturing two types of atomic bombs , and the 509th composite group Come_together of the united states army air forces ( usaaf ) was equipped Supply with the specialized Education_teaching silverplate version of the boeing b-29 superfortress that could deliver Military_operation them from tinian in the mariana islands .

Those teams were instead replaced Removing by a composite International XI team .