▁ 2 0 0 0 ▁BC , ▁the ▁development ▁of ▁" pre - contact " ▁society , ▁Spanish ▁colon ization ▁in ▁the ▁ 1 7 th ▁century ▁and ▁the ▁present ▁American ▁rule ▁of ▁the ▁island ▁since ▁the ▁ 1 8 9 8 ▁Spanish – American ▁War . ▁Gu am ' s ▁history ▁of ▁colonial ism ▁is ▁the ▁longest ▁among ▁the ▁Pacific ▁islands . ▁ ▁Gu am ▁prior ▁to ▁European ▁contact ▁ ▁M igr ations ▁It ▁is ▁believed ▁that ▁Gu am ▁was ▁first ▁discovered ▁by ▁se af aring ▁people ▁who ▁migr ated ▁from ▁S out heast ▁Asia ▁around ▁ 2 0 0 0 ▁BC . ▁The ▁original ▁inhabitants ▁of ▁Gu am ▁are ▁believed ▁to ▁be ▁descend ants ▁of ▁Aust ron esian ▁people ▁origin ating ▁from ▁S out heast ▁Asia ▁as ▁early ▁as ▁ 2 0 0 0 ▁BC , ▁having ▁lingu istic ▁and ▁cultural ▁similar ities ▁to ▁Malays ia , ▁Indones ia , ▁and ▁the ▁Philippines . ▁These ▁people ▁evol ved ▁into ▁the ▁Cham or ro ▁people . ▁They ▁fl our ished ▁as ▁an ▁advanced , ▁h ort icult ural ▁and ▁hunting ▁society . ▁They ▁were ▁expert ▁se af ar ers ▁and ▁sk illed ▁craft s men ▁familiar ▁with ▁intr icate ▁we aving ▁and ▁detailed ▁pot tery ▁who ▁built ▁unique ▁houses ▁and ▁can o es ▁su ited ▁to ▁this ▁region ▁of ▁the ▁world . ▁ ▁Most ▁of ▁what ▁is ▁known ▁about ▁Pre - Contact ▁(" An cient ") ▁Cham or ros ▁comes ▁from ▁leg ends ▁and ▁myth s , ▁arch ae ological ▁evidence ,