Mezue ahịrịokwu na-esonụ: N'afọ 1929, Groves gawara Nicaragua na-elekọta otu ụlọ ọrụ nke 1st Engineers dị ka akụkụ nke njem nke ebumnuche ya bụ ime nyocha maka Inter-Oceanic Nicaragua Canal. Ịgbaso
Ala ọma jijiji nke Nicaragua na 1931, Groves weghaara ọrụ maka usoro mmiri nke Managua, nke e nyere ya ihe nrite nke Nicaraguan Presidential Medal of Merit. A buliri Groves n'ọkwa onye isi n'abalị iri abụọ n'ọnwa Ọktoba n'afọ 1934. Ọ gara ụlọ akwụkwọ Command na General Staff na Fort Leavenworth, Kansas, na 1935 na 1936, mgbe nke ahụ gasịrị, e zigara ya na Kansas City, Missouri, dị ka onye na-enyere onye isi nke Missouri River Division aka. N'afọ 1938 na 1939 ọ gara ụlọ akwụkwọ ndị agha. N'ụbọchị mbụ nke ọnwa Julaị n'afọ 1939, e zigara ya n'ụlọọrụ General Staff na Washington, D.C.