New Mexico Territorial Laws and Treaties NM TERR LAWS ORGANIC ACT § 6

Every free white male inhabitant, above the age of twenty-one years, who shall have been a resident of said territory at the time of the passage of this act, shall be entitled to vote at the first election, and shall be eligible to any office within the said territory; but the qualifications of voters and of holding office, at all subsequent elections, shall be such as shall be prescribed by the legislative assembly: provided, that the right of suffrage, and of holding office, shall be exercised only by citizens of the United States, including those recognized as citizens by the treaty with the republic of Mexico, concluded February second, eighteen hundred and forty-eight.