The Mexican-American war followed a range of disputes between the countries. Annexation of Texas raised most concerns. The territory originally belonged to Mexico but only until 1838 when the US settlers of Texas proclaimed its independence. The Republic of Texas remained autonomous for 9 more years until the US recognized Texas as a slave state. In 1845, the US annexed Texas having evoked indignation in Mexico. The latter never recognized Texas as an independent unity, therefore, observed the annexation as a clear trespass on their territory. The Treaties of Velasco conducted after the defeat of the Mexican army in the battle of San Jacinto (1836) also did not please Mexico. The two documents – the public treaty and the secret agreement – were signed by captive Mexican general Santa Anna. The public treaty proclaimed the withdrawal of the Mexican army beyond the Rio Grande, the release of prisoners and restoration of losses done to Texas. In the secret treaty, Santa Anna promised to use his authority to secure the independence of Texas and to work on enhancing commerce between Texas and Mexico. However, the Texas army refused to let Santa Anna go, and the treaties were declared void. Mexico did not acknowledge the southern border of Texas as far as the Rio Grande river and feared their territory will be consumed by the US. Besides the argument for borderlands, money was another problem between the US and Mexico. Mexico owed the US about $4.5 million lost in the Mexican War for Independence. The US expected Mexico to pay off the debt, however, the US was ready to forgive the debt for the sake of establishing friendly relationships. The US government further attempted to purchase the New Mexico and California, but Mexican government was discouraged in losing their land. They refused to negotiate with the US government, which added more fuel to fire.