Final answer:
Texas declared its independence as the Republic of Texas in 1836 due to political, religious, and economic tensions. The revolution ended with the signing of the Treaty of Velasco, which marked the end of hostilities between Mexico and Texas, but did not fully recognize Texas as an independent republic. The annexation of Texas to the United States later became a cause of the Mexican-American War.
Step-by-step explanation:
The circumstances under which Texas declared its independence and the Texas Declaration of Independence was signed were a result of various factors and events. In 1835-1836, tensions rose in Texas due to political and religious differences, as well as the American reliance on slave labor. These tensions led to the Texas Revolution, during which Texas declared its independence as the Republic of Texas.
Following the Battle of San Jacinto, where the Texan army led by Sam Houston achieved a decisive victory, Santa Anna was forced to sign the public Treaty of Velasco, which ended hostilities between Mexico and Texas but did not recognize the Republic. While Texas remained an independent nation from 1836 to 1846, there were discussions of possible annexation to the United States, which later became a contributing factor of the Mexican-American War.