The project for the annexation of Texas, which was first officially broached in the last year of President Tyler's administration, acquired more and more weight and influence, until finally, in March, 1845, an act to that effect was passed by both Houses of Congress, and was soon after ratified by the Texian government. Mexico, although the independence of Texas had been long before _de facto_ secured, stoutly protested against the annexation. The special American envoy sent to the Mexican capital to attempt an adjustment of this and other difficulties, was refused a hearing, and great preparations were carried on by the Mexican government for another invasion of Texas. In June, General Taylor received orders to advance with his troops over the Sabine, and protect all of the territory east of the Rio Grande, over which Texas exercised jurisdiction. He accordingly marched into Texas, and in August concentrated his forces, amounting to about 3000 men, at Corpus Christi. Receiving orders from Washington to proceed to the Rio Grande, the general, with his little army, moved westward in March, 1846: and after considerable suffering from the heal and the want of food and water, reached the banks of the river opposite Matamoras on the 28th of the month. Colonel Twiggs, with a detachment of dragoons, in the mean time took possession of Point Isabel, situated on an arm of the Gulf, about 25 miles east. General Taylor took every means to assure the Mexicans that his purpose was not war, nor violence in any shape, but solely the occupation of the Texian territory to the Rio Grande, until the boundary should be definitively settled by the two republics.