Narrative History of Texas Annexation, Secession, and Readmission to the Union Texans voted in favor of annexation to the United States in the first election following independence in 1836. However, throughout the Republic period (1836-1845) no treaty of annexation negotiated between the Republic and the United States was ratified by both nations.
When all attempts to arrive at a formal annexation treaty failed, the United States Congress passed--after much debate and only a simple majority--a Joint Resolution for Annexing Texas to the United States. Under these terms, Texas would keep both its public lands and its public debt, it would have the power to divide into four additional states "of convenient size" in the future if it so desired, and it would deliver all military, postal, and customs facilities and authority to the United States government. (Neither this joint resolution or the ordinance passed by the Republic of Texas' Annexation Convention gave Texas the right to secede.)
In July 1845, a popularly-elected Constitutional Convention met in Austin to consider both this annexation proposal as well as a proposed peace treaty with Mexico which would end the state of war between the two nations, but only if Texas remained an independent country.
The Convention voted to accept the United States' proposal, and the Annexation Ordinance was submitted to a popular vote in October 1845. The proposed Annexation Ordinance and State Constitution were approved by the Texas voters and submitted to the United States Congress.
The United States House and Senate, in turn, accepted the Texas state constitution in a Joint Resolution to admit Texas as a State which was signed by the president on December 29, 1845 . Although the formal transfer of government did not occur until February 19, 1846, Texas statehood dates from the 29th of December.