Mezue ahịrịokwu na-esonụ: Nwa onye ụkọchukwu ndị agha U.S., Groves biri n'ụlọ ọrụ ndị agha dị iche iche n'oge ọ bụ nwata. Na 1918, ọ gụsịrị akwụkwọ na klas ya nke anọ na U.S. Military Academy na West Point ma nye ya ọrụ na ndị ọrụ injinia nke ndị agha United States. N'afọ 1929, ọ gara Nicaragua dịka akụkụ nke njem iji mee nyocha maka Inter-Oceanic Nicaragua Canal. Ịgbaso
ala ọma jijiji nke 1931, Groves weghaara sistemụ mmiri nke Managua, nke e nyere ya ihe nrite nke Nicaraguan Presidential Medal of Merit. Ọ gara ụlọ akwụkwọ Command na General Staff na Fort Leavenworth, Kansas, na 1935 na 1936; na Army War College na 1938 na 1939, mgbe nke ahụ gasịrị, e zigara ya na Ngalaba War General Staff. Groves zụlitere "aha ọma dị ka onye na-eme ihe, onye ọkwọ ụgbọala, na onye na-agbasosi ọrụ ike" na 1940 ọ ghọrọ onye inyeaka pụrụ iche maka iwu ihe owuwu nke Quartermaster General, nke e nyere ọrụ inyocha ebe ndị a na-ewu ihe owuwu ma na-enyocha ọganihu ha. N'August 1941, e kenyere ya ọrụ iwu nnukwu ụlọ ọrụ maka ndị ọrụ 40,000 nke Ngalaba Agha bụ́ nke mesịrị ghọọ Pentagon.