The Republic of Texas was officially declared a free and independent country March 2, 1836, when the Texas Declaration of Independence was signed at Washington-on-the-Brazos. On April 21, 1836 General Sam Houston and the Texas Army convinced Mexico's General Santa Anna of that fact (at least they convinced him while he was in captivity). The United States of America's President James K. Polk signed the Texas Annexation Act on December 29, 1845. After almost ten years of being an independent country, the Republic of Texas ended and the State of Texas began February 19, 1846 at a ceremony held in Austin, Texas. The Birthday of Texas is always celebrated on March 2, as Texas Independence Day.
When Texas was annexed to the United Sates it had been a separate and independent country for almost ten years. As an independent country, Texas claimed a territory that was much larger than its present boundries. During the years Texas was independent, she had also built up a sizable national debt, thanks in large part to the spending excesses of Mirabeau B. Lamar. As part of the annexation agreement, Texas ceded a large portion of her national territory to the United States for retirement of the national debt. This parcel of ceded territory has since become part of the states of New Mexico, Kansas, Oklahoma, Colorado and Wyoming.