Dee ihe na-aga n'ihu maka paragraf a - Na Machị 1944, Simpson so n'ụgbọ mmiri ndị na-ebute ụgbọ mmiri n'ime Ngalaba nke 3 nke ndị agha mmiri ma sonye na Landing na Emirau
, bụ́ nke na- enwetaghị mmegide ọ bụla. E buliri ya n'ọkwa lieutenant colonel n'ọnwa Eprel 1944 ma nye ya iwu ka ọ laghachi na States otu ọnwa mgbe nke ahụ gasịrị. Mgbe ọ laghachiri na steeti ahụ, enyere Simpson iwu ka ọ gaa n'ụlọ akwụkwọ ndị agha na Command and Staff College na Fort Leavenworth, Kansas wee gụchaa na Nọvemba nke afọ ahụ.