Why did polk want mexico to fire first

President James K. Polk went to war with Mexico and got California and other lands in the West. The war's aftermath brought forward issues of the citizenship status and property rights of Mexicans who remained in the new American territories.

Since the 1820s, Mexico had encouraged Americans to settle in its state of Texas. By the 1830s, Americans outnumbered native Mexicans in Texas by four to one. When a new Mexican constitution did away with state rights, the American settlers rebelled and established an independent country in 1836. Mexico, however, did not formally recognize the Republic of Texas.

Texas claimed the boundary with Mexico was at Rio Grande River. Mexico argued that it was at the Nueces River. The land in between these rivers included thousands of square miles and a few hundred settlers, few of whom were Texans.

In 1845, Congress voted to annex Texas and admit it as a state. Shortly afterward, James K. Polk took office as the new U. S. president. Polk was a Democrat and a strong advocate of national expansion.

President Polk had a short list of "great measures" he intended to accomplish. Among them was the acquisition of Mexican California. Gold had not been discovered there yet, but Polk wanted California and its magnificent San Francisco Bay as the American gateway to trade with China and other Asian nations. Polk was worried that other nations, such as England or France, might take California if the United States did not act.

US expansionists wanted California to thwart British ambitions in the area and to gain a port on the Pacific Ocean. Polk authorized Slidell to forgive the $3 million owed to US citizens for damages caused by the Mexican War of Independence and pay another $25 to $30 million in exchange for the two territories.