am : ▁ ▁Gu am ▁– ▁organized , ▁un in cor por ated ▁territory ▁of ▁the ▁United ▁States ▁of ▁America ▁that ▁compr ises ▁the ▁island ▁of ▁Gu am ▁in ▁the ▁western ▁North ▁Pacific ▁Ocean . ▁ ▁It ▁is ▁one ▁of ▁five ▁U . S . ▁territ ories ▁with ▁an ▁established ▁civil ian ▁government . ▁ ▁The ▁island ' s ▁capital ▁is ▁H ag å t ña ▁( former ly ▁Ag ana ). ▁ ▁Gu am ▁is ▁the ▁largest ▁and ▁southern most ▁of ▁the ▁Mar iana ▁Islands . ▁The ▁Cham or ros , ▁Gu am ' s ▁ind igen ous ▁inhabitants , ▁first ▁populated ▁the ▁island ▁approximately ▁ 4 , 0 0 0 ▁years ▁ago . ▁Disc over ed ▁by ▁the ▁Spanish ▁expedition ▁of ▁Ferdinand ▁Mag ellan ▁in ▁ 1 5 2 1 , ▁the ▁island ▁has ▁a ▁long ▁history ▁of ▁European ▁colonial ism ▁beginning ▁in ▁the ▁ 1 6 th ▁century , ▁and ▁especially ▁in ▁ 1 6 6 8 ▁with ▁the ▁arrival ▁of ▁Spanish ▁sett lers ▁including ▁P adre ▁San ▁V itor es , ▁a ▁Catholic ▁mission ary . ▁Gu am ▁and ▁the ▁rest ▁of ▁the ▁Mar iana ▁Islands ▁were ▁integrated ▁in ▁the ▁Spanish ▁East ▁Ind ies ▁since ▁ 1 5 6 5 . ▁The ▁island ▁was ▁a ▁major ▁stop over ▁for ▁Man ila ▁G alle ons ▁sail ing ▁from ▁A cap ul co , ▁until ▁ 1 8 1 5 . ▁Gu am ▁was ▁taken ▁over ▁from ▁Spain ▁by ▁the ▁United ▁States ▁during ▁the ▁Spanish – American ▁War ▁in ▁ 1