In 200 words explain who took part in the victory for the U.S during world war 2 and why did they play a huge role?

A big group of people who helped where jewish scientists who escaped Germany from 1933 to 1936. These people went on to work of the U.S governement in the Manhattan Project and created the first atomic bomb. Another group of people where some of the segregated units during the war such as the red tails. A only african American fighter battalion which assisted in bomber escorted and scouting missions. The 2nd group was a only Japanese unit. The 442nd. This unit was the most decorated and still is the most decorated unit to have ever served in the U.S Military. with 21 medal of honors awarded.