▁entered ▁politics , ▁becoming ▁a ▁member ▁of ▁the ▁Legisl ative ▁Assembly ▁of ▁V ancouver ▁Island ▁from ▁ 1 8 6 3 ▁until ▁its ▁union ▁with ▁the ▁Col ony ▁of ▁British ▁Columbia ▁in ▁ 1 8 6 6 . ▁He ▁advanced ▁the ▁second ▁cause ▁through ▁his ▁position ▁as ▁a ▁member ▁of ▁the ▁assembly ▁of ▁the ▁merged , ▁larger ▁British ▁Columbia ▁from ▁ 1 8 6 7 – 6 8 ▁and ▁ 1 8 7 0 – 7 1 , ▁and ▁as ▁the ▁leading ▁force ▁( with ▁Robert ▁Be aven ▁and ▁John ▁Rob son ) ▁behind ▁the ▁col ony ' s ▁Confeder ation ▁League . ▁Through ▁the ▁instrument al ▁role ▁De ▁Cos mos ▁played ▁in ▁real izing ▁these ▁two ▁goals , ▁he ▁earned ▁for ▁himself ▁his ▁reputation ▁as ▁British ▁Columbia ' s ▁Father ▁of ▁Confeder ation . ▁ ▁At ▁the ▁time ▁of ▁British ▁Columbia ' s ▁entry ▁into ▁Confeder ation ▁on ▁July ▁ 2 0 , ▁ 1 8 7 1 , ▁De ▁Cos mos ▁was ▁the ▁leading ▁pro - Conf eder ation ▁figure ▁in ▁the ▁new ▁province . ▁ ▁That ▁year , ▁he ▁was ▁elected ▁to ▁represent ▁Victoria ▁in ▁both ▁the ▁provincial ▁legisl ature ▁and ▁the ▁House ▁of ▁Commons . ▁Despite ▁his ▁prom in ence ▁— ▁or ▁perhaps ▁because ▁of ▁it ▁— ▁Lieutenant ▁Governor ▁Sir ▁Joseph ▁Tr utch ▁passed ▁over ▁De ▁Cos mos ▁for ▁the ▁job ▁of ▁Premier , ▁instead ▁asking ▁John ▁F oster ▁Mc Cre ight ▁to ▁assume ▁the ▁position . ▁ ▁Icon oc last ic ▁reputation ▁ ▁Und ou bt edly ,