Kuenderera mberi kweiyi ndima - Sangano iri rakatanga kurambwa naPurezidhendi Woodrow Wilson, uyo aidavira kuti United States inofanira kuva munzvimbo isina kwayakarerekera kuitira kuti igadzirise rugare muEurope. Masangano anoverengeka akaumbwa akapoteredza Sangano reKugadzirira uye akabata mapati uye akaronga kupikisa mitemo yaWilson. Pashure pokunge "Lusitania" yanyudzwa nezvikepe zveU-boats zveGermany pana May 7, 1915, uye Pancho Villa akatanga kurwisa kwake
pakurwisa Columbus, New Mexico, chimiro chaWilson chakachinja. Congress yakapasa National Defense Act ya 1916 muna June 1916 kuti ibvumire kuwedzera kukura kweuto reU.S. kubva kuvarume 100 000 muna 1916 kusvika ku200 000 vari mubasa rinoshanda uye 400 000 muU.S. National Guard, na1921. Yakagoverawo wedzero huru yenguva refu muU.S. Navy.