New Mexico: Polity Style: 1846-1850

18 Aug 1846	following the invasion of Mexico by the armed forces of the United States, the Army of the West takes possession of Santa Fe, the capital of the Department of Nuevo México (Departamento de Nuevo México) on 18 Aug 1846 (United States Congressional Serial Set, 30th Congress, 1st session, House Executive Document No. 60, pp. 21-22; Turner Journals, p. 72)
22 Aug 1846	Nuevo México is declared a possession of the United States under the name of the Territory of New Mexico, in accordance with a proclamation issued by the Commander of the Army of the West at Santa Fe on 22 Aug 1846 (United States Congressional Serial Set, 30th Congress, 1st session, House Executive Document No. 60, pp. 22-23)
22 Aug 1846 - 9 Sep 1850	Territory of New Mexico :: Territorio de Nuevo México
30 May 1848	the territories of Mexico occupied by the armed forces of the United States are incorporated into the United States within the boundaries defined by a treaty concluded by the plenipotentiaries of both nations at Guadalupe Hidalgo, Mexico, on 2 Feb 1848 (effective upon the exchange of ratifications at Querétaro on 30 May 1848) (Statutes at Large, 9:922-943; Correo Nacional, No. 121, 9 Jun 1848, pp. 1-4)
25 May 1850	the Constitution of the State of New Mexico is adopted at a session of the Convention held in Santa Fe on 25 May 1850, pending the ratification by the people of New Mexico (New Mexico Constitution 1850, p. 44) [1]
9 Sep 1850	a portion of the territory of the United States is erected into a temporary government by the name of the Territory of New Mexico in accordance with an act passed by the Congress of the United States (Senate on 9 Aug 1850, House of Representatives on 6 Sep 1850, with amendments; Senate concurs in the amendments on 9 Sep 1850), signed into law on 9 Sep 1850 (Statutes at Large, 9:446-452) [2][3]

The civil and military Governor of New Mexico, Munroe, complied with the request of the Convention to call an election under the Constitution adopted on 25 May 1850. The vote was duly held, resulting in the election of Henry Connelly and Manuel Álvarez as Governor and Lieutenant Governor. As Connelly was absent from New Mexico, Álvarez claimed the right to assume office as Acting Governor, but Munroe refused to transfer executive authority to the elected officials.
Full title: An Act proposing to the State of Texas the Establishment of her Northern and Western Boundaries, the Relinquishment by the said State of all Territory claimed by her exterior to said Boundaries, and of all her Claims upon the United States and to establish a territorial Government for New Mexico.
The Territory of New Mexico, created under federal law, included the former Department of Nuevo México, and parts of Alta California and Texas.