▁native ▁death s ▁after ▁ 1 8 4 8 ▁were ▁murder . ▁ ▁In ▁ 1 8 3 7 – 3 8 , ▁a ▁major ▁small po x ▁ep ide mic ▁dev ast ated ▁native ▁tribes ▁north ▁of ▁San ▁Francisco ▁Bay , ▁in ▁the ▁juris diction ▁of ▁Mission ▁San ▁Francisco ▁Sol ano . ▁General ▁Mar iano ▁Valle jo ▁estimated ▁that ▁ 7 0 , 0 0 0 ▁died ▁from ▁the ▁disease . ▁Valle jo ' s ▁al ly , ▁chief ▁Sem - Y eto , ▁was ▁one ▁of ▁the ▁few ▁n atives ▁to ▁be ▁v acc in ated , ▁and ▁one ▁of ▁the ▁few ▁to ▁surv ive . ▁ ▁When ▁the ▁mission ▁properties ▁were ▁sec ular ized ▁between ▁ 1 8 3 4 ▁and ▁ 1 8 3 8 , ▁the ▁approximately ▁ 1 5 , 0 0 0 ▁resident ▁ne oph y tes ▁lost ▁whatever ▁protection ▁the ▁mission ▁system ▁afford ed ▁them . ▁While ▁under ▁the ▁sec ular ization ▁laws ▁the ▁n atives ▁were ▁to ▁receive ▁up ▁to ▁one - half ▁of ▁the ▁mission ▁properties , ▁this ▁never ▁happened . ▁The ▁n atives ▁lost ▁whatever ▁stock ▁and ▁mov able ▁property ▁they ▁may ▁have ▁accum ulated . ▁When ▁California ▁became ▁a ▁U . S . ▁state , ▁California ▁law ▁stri pped ▁them ▁of ▁legal ▁title ▁to ▁the ▁land . ▁In ▁the ▁Act ▁of ▁September ▁ 3 0 , ▁ 1 8 5 0 , ▁Congress ▁appropri ated ▁funds ▁to ▁allow ▁the ▁President ▁to ▁appoint ▁three ▁Commission ers , ▁O . ▁M . ▁W