▁the ▁California ▁miss ions . ▁The ▁Mission ▁archive ▁is ▁the ▁oldest ▁library ▁in ▁the ▁State ▁of ▁California ▁that ▁still ▁remains ▁in ▁the ▁hands ▁of ▁its ▁found ers , ▁the ▁Francis c ans ▁( it ▁is ▁the ▁only ▁mission ▁where ▁they ▁have ▁maintained ▁an ▁un inter rupted ▁presence ). ▁Begin ning ▁with ▁the ▁writ ings ▁of ▁Hub ert ▁How e ▁B anc ro ft , ▁the ▁library ▁has ▁served ▁as ▁a ▁center ▁for ▁historical ▁study ▁of ▁the ▁miss ions ▁for ▁more ▁than ▁a ▁century . ▁In ▁ 1 8 9 5 ▁journalist ▁and ▁historian ▁Charles ▁F let cher ▁L umm is ▁critic ized ▁the ▁Act ▁and ▁its ▁results , ▁saying : ▁ ▁California ▁state hood ▁( 1 8 5 0 ▁and ▁beyond ) ▁▁ ▁P rec ise ▁figures ▁rel ating ▁to ▁the ▁population ▁decl ine ▁of ▁California ▁ind igen es ▁are ▁not ▁available . ▁One ▁writer , ▁Gregory ▁Or f ale a , ▁estimates ▁that ▁pre - contact ▁population ▁was ▁reduced ▁by ▁ 3 3 ▁percent ▁during ▁Spanish ▁and ▁Mexican ▁rule , ▁mostly ▁through ▁introduction ▁of ▁European ▁dise ases , ▁but ▁much ▁more ▁after ▁the ▁United ▁States ▁take over ▁in ▁ 1 8 4 8 . ▁By ▁ 1 8 7 0 , ▁the ▁loss ▁of ▁ind igen ous ▁lives ▁had ▁become ▁cat ast roph ic . ▁Up ▁to ▁ 8 0 ▁percent ▁died , ▁leaving ▁a ▁population ▁of ▁about ▁ 3 0 , 0 0 0 ▁in ▁ 1 8 7 0 . ▁Or f ale a ▁claims ▁that ▁nearly ▁half ▁of ▁the