▁built ▁the ▁$ 3 0 ▁million ▁N ava jo ▁Or dn ance ▁Dep ot , ▁which ▁required ▁ 8 , 0 0 0 ▁workers ▁to ▁build ▁and ▁ 2 , 0 0 0 ▁employees ▁upon ▁completion . ▁Many ▁of ▁the ▁staff ▁were ▁Native ▁Americans . ▁ ▁Intern ment ▁cam ps ▁▁ ▁On ▁March ▁ 1 8 , ▁ 1 9 4 2 , ▁President ▁Franklin ▁Ro ose vel t ▁signed ▁Executive ▁Order ▁ 9 1 0 2 , ▁which ▁created ▁the ▁War ▁Rel ocation ▁Author ity ▁for ▁the ▁intern ment ▁of ▁Japanese - Amer icans . ▁Most ▁of ▁the ▁inter ne es ▁were ▁from ▁the ▁West ▁Coast Al aska , ▁Washington , ▁Oregon , ▁and ▁California and ▁they ▁were ▁sent ▁to ▁a ▁series ▁of ▁ten ▁cam ps ▁distributed ▁across ▁the ▁country . ▁Two ▁of ▁the ▁largest ▁cam ps ▁were ▁located ▁in ▁southern ▁Arizona . ▁ ▁The ▁first ▁of ▁the ▁cam ps ▁was ▁the ▁Post on ▁War ▁Rel ocation ▁Center , ▁which ▁was ▁built ▁within ▁the ▁Colorado ▁River ▁Indian ▁Res ervation , ▁near ▁the ▁town ▁of ▁Post on , ▁in ▁early ▁ 1 9 4 2 . ▁The ▁second , ▁the ▁G ila ▁River ▁War ▁Rel ocation ▁Center , ▁was ▁built ▁shortly ▁there after ▁and ▁located ▁in ▁the ▁G ila ▁River ▁Indian ▁Res ervation , ▁near ▁the ▁town ▁of ▁R ivers . ▁Both ▁eventually ▁bl oss omed ▁into ▁the ▁third ▁and ▁fourth ▁largest ▁cities ▁in ▁Arizona ▁during ▁the ▁war ▁with ▁populations ▁of ▁ 1 8 , 0 0 0 ▁and ▁ 1 3 ,