 Nyorai kupfuurira kweiyi ndima - Pana 1 June 1925, McClellan akaendeswa kuMarine Barracks paPearl Harbor, muHawaii, ndokutora Manookian naye. McClellan akabva kuHawaii musi wa15 Mbudzi 1927, paakafamba kwenguva pfupi muWestern Recruiting Region. Musi wa19 October 1928 akabatana ne5th Marine Regiment kuti ashande somutori wemifananidzo wokupamba kweNicaraguakusvikira pana 24 July wegore rinotevera. Pashure pokumira kwenguva pfupi muQuantico kunopinda Field Officers Course, akadzoka kuzotungamirira Chikamu cheNhoroondo zvakare musi wa20 June 1930. Munguva yorwendo rwechipiri urwu, akaunganidza nhoroondo yemavhoriyamu manomwe yeCorps, asi Great Depression yakaita kuti kudhinda kusakwanisika, kwaakashandisa makopi akaitwa nemaoko kuti agoverwe. 