▁in ▁the ▁Marine ▁Corps ▁on ▁October ▁ 9 , ▁ 1 9 1 2 ▁at ▁Philadelphia , ▁Pennsylvania . ▁ ▁Following ▁initial ▁training ▁and ▁a ▁brief ▁two - month ▁st int ▁at ▁Camp ▁Meyer , ▁Cuba ▁in ▁ 1 9 1 3 , ▁Gro ff ▁was ▁assigned ▁to ▁the ▁ 4 6 th ▁Company , ▁Special ▁Service ▁Squadron , ▁which ▁sa iled ▁for ▁Mexico ▁in ▁April ▁ 1 9 1 4 ▁on ▁board ▁the ▁USS ▁New ▁York ▁( BB - 3 4 ). ▁ ▁While ▁the ▁New ▁York ▁arrived ▁too ▁late ▁to ▁take ▁part ▁in ▁the ▁actual ▁Battle ▁of ▁Ver ac ru z , ▁Gro ff ▁participated ▁in ▁the ▁United ▁States ▁occupation ▁of ▁Ver ac ru z ▁from ▁May – J une ▁ 1 9 1 4 . ▁ ▁He ▁spent ▁most ▁of ▁the ▁remainder ▁of ▁the ▁year ▁as ▁a ▁gun ▁stri ker ▁with ▁the ▁ 4 6 th ▁Co ., ▁ 5 th ▁Marine ▁Regiment ▁on ▁board ▁the ▁USS ▁Han cock ▁( AP - 3 ) ▁near ▁Santo ▁Dom ingo ▁City , ▁Domin ican ▁Republic . ▁ ▁In ▁ 1 9 1 5 , ▁H ait i ▁was ▁rock ed ▁by ▁revolution s , ▁which ▁had ▁begun ▁the ▁previous ▁year . ▁By ▁then , ▁Gro ff ▁was ▁a ▁member ▁of ▁the ▁Marine ▁Det achment ▁on ▁board ▁the ▁USS ▁Washington ▁( AC R - 1 1 ). ▁He ▁participated ▁in ▁the ▁initial ▁landing ▁force ▁eng agement ▁at ▁Port - au - Pr ince ▁on ▁July ▁ 2 8 , ▁ 1 9 1