Kammala wannan jumla: An haifi Granger a Zanesville, Ohio. Ya kammala karatunsa daga Kwalejin Sojojin Amurka, yana matsayi na 28 a cikin aji na 1838. Granger ya zama babban jami'in soja na farko a 1839. Ya yi aiki a matsayin jami'in a cikin
Seminole War, kuma ya kasance mataimakin malami na dabaru a West Point a 1843 / 44. A lokacin yakin Mexican-American, Granger ya ci gaba da zama kyaftin a ranar 8 ga Satumba, 1847. Lokacin da yakin ya ƙare, an sanya shi zuwa jerin posts a kan iyakar Texas.