▁with ▁the ▁on set ▁of ▁the ▁Mexican ▁War ▁of ▁Independ ence ▁in ▁ 1 8 1 0 , ▁this ▁support ▁largely ▁disappeared , ▁and ▁miss ions ▁and ▁converts ▁were ▁left ▁on ▁their ▁own . ▁As ▁of ▁ 1 8 0 0 , ▁native ▁labor ▁had ▁made ▁up ▁the ▁back bone ▁of ▁the ▁colonial ▁economy . ▁ ▁Ar gu ably ▁" the ▁worst ▁ep ide mic ▁of ▁the ▁Spanish ▁Era ▁in ▁California " ▁was ▁known ▁to ▁be ▁the ▁meas les ▁ep ide mic ▁of ▁ 1 8 0 6 , ▁where in ▁one - qu arter ▁of ▁the ▁mission ▁Native ▁American ▁population ▁of ▁the ▁San ▁Francisco ▁Bay ▁Area ▁died ▁of ▁the ▁meas les ▁or ▁related ▁comp lications ▁between ▁March ▁and ▁May ▁of ▁that ▁year . ▁In ▁ 1 8 1 1 , ▁the ▁Spanish ▁Vic ero y ▁in ▁Mexico ▁sent ▁an ▁inter rog atorio ▁( question naire ) ▁to ▁all ▁of ▁the ▁miss ions ▁in ▁Al ta ▁California ▁regarding ▁the ▁custom s , ▁disposition , ▁and ▁condition ▁of ▁the ▁Mission ▁Indians . ▁The ▁rep lies , ▁which ▁varied ▁greatly ▁in ▁the ▁length , ▁spirit , ▁and ▁even ▁the ▁value ▁of ▁the ▁information ▁contained ▁there in , ▁were ▁collected ▁and ▁pre fac ed ▁by ▁the ▁Father - Pres idente ▁with ▁a ▁short ▁general ▁statement ▁or ▁abstract ; ▁the ▁compilation ▁was ▁there up on ▁forward ed ▁to ▁the ▁vic er eg al ▁government . ▁The ▁contemporary ▁nature ▁of ▁the ▁responses , ▁no ▁matter ▁how ▁incomplete ▁or ▁bi ased ▁some ▁may ▁be , ▁are ▁non eth eless