The Eastern Mandates are part of the Marshall Islands where Brostrom and the 17th Infantry Division invaded Kwajalein atoll after four months of training in Hawaii. Under their new leader Major General C. H. Corlett, the amphibious assaults on the 42 islands of the atoll went "most nearly perfect". It is not certain which specific island (s) that F Company captured. The division returned to Hawaii for rest and recuperation, and then trained for the next assault.