He had substantial involvement in negotiating treaties between California Native American Indian tribes and the United States of America.

[9] After the cholera epidemic swept Brownsville in February through April 1849,[10] upon hearing news of gold being discovered, Wozencraft decided to seek his fortune in California.

[12] Wozencraft spoke against the admission of African Americans to California: We have declared, by a unanimous vote, that neither slavery nor involuntary servitude shall ever exist in this State.

I desire now to cast my vote in favor of the proposition just submitted, prohibiting the negro race from coming amongst us; and this I profess to do as a philanthropist, loving my kind, and rejoicing in their rapid march toward perfectibility.

We see evidence of this wherever they are brought in contact; we see the instinctive feeling of the negro is obedience to the white man, and, in all instances, he obeys him, and is ruled by him.

[19] Between March 19, 1851, and January 7, 1852, Wozencraft, McKee and Barbour traversed California and negotiated 18 treaties with Native American tribes.

[23][24] In 1859 Wozencraft successfully lobbied the California State Legislature to provisionally allocate 3,000,000 acres (12,141 km2) of the Colorado Desert to himself for the scheme.

[4][24] Wozencraft required passage of federal legislation (e.g. H.R.3219[23]) to finalize the land allocation approved by the state legislature.

[22]Nineteenth century evaluations are likewise scathing: There was a very general impression in the state, and apparently pretty well founded, that [Wozencraft, McKee and Barbour] knew little about the country and still less about the Indians; and that everything they did was a mistake and almost everything in excess of their powers.