ian ▁Field s ▁dimin ished . ▁ ▁In ▁ 1 8 6 8 ▁the ▁leading ▁Manh attan ▁club , ▁Mut ual , ▁shift ed ▁its ▁home ▁games ▁to ▁the ▁Union ▁Gr ounds ▁in ▁Brook lyn . ▁ ▁In ▁ 1 8 8 0 , ▁the ▁found ers ▁of ▁the ▁New ▁York ▁Metropol it ans ▁and ▁New ▁York ▁Gi ants ▁finally ▁succeeded ▁in ▁sit ing ▁a ▁ball park ▁in ▁Manh attan ▁that ▁became ▁known ▁as ▁the ▁Pol o ▁Gr ounds . ▁▁ 2 0 th ▁century ▁F ew ▁non wh ites ▁had ▁settled ▁in ▁Hob oken ▁by ▁ 1 9 0 1 . ▁The ▁Brook lyn ▁E agle ▁claimed ▁that ▁an ▁un written ▁su nd own ▁town ▁policy ▁prevent ed ▁African ▁Americans ▁from ▁res iding ▁or ▁working ▁there . ▁ ▁World ▁War ▁I ▁ ▁When ▁the ▁U . S . ▁entered ▁World ▁War ▁I , ▁the ▁Hamburg - American ▁Line ▁pi ers ▁in ▁Hob oken ▁( and ▁New ▁Orleans ) ▁were ▁taken ▁under ▁em inent ▁domain . ▁Federal ▁control ▁of ▁the ▁port ▁and ▁anti - G erman ▁sentiment ▁led ▁to ▁part ▁of ▁the ▁city ▁being ▁placed ▁under ▁mart ial ▁law , ▁and ▁many ▁German ▁imm igr ants ▁were ▁for ci b ly ▁moved ▁to ▁Ell is ▁Island ▁or ▁left ▁the ▁city ▁of ▁their ▁own ▁accord . ▁Hob oken ▁became ▁the ▁major ▁point ▁of ▁emb ark ation ▁and ▁more ▁than ▁three ▁million ▁soldiers , ▁known ▁as ▁" d ough bo ys ", ▁passed ▁through ▁the ▁city . ▁Their ▁hope ▁for ▁an ▁early ▁return ▁led ▁to