In your opinion what was the most important effect of annexion Mexican cessiom?

* Increased the size of the United States by about one-third: The Mexican Cession added over 500,000 square miles to the United States. This new territory included the present-day states of California, Nevada, Utah, Arizona, and New Mexico, as well as parts of Colorado, Wyoming, and Kansas.

* Increased the population of the United States by about one-tenth: The Mexican Cession brought an estimated 80,000 to 100,000 people into the United States. These new citizens were mostly Hispanic and Native American, and they added to the diversity of the country.

* Ignited the Mexican-American War: The Mexican Cession was the main cause of the Mexican-American War (1846-1848). The United States wanted to annex Texas, but Mexico refused to recognize Texas as an independent country. The United States then annexed Texas and sent troops into the disputed territory, which led to war.

* Resulted in the construction of the Transcontinental Railroad: The Mexican Cession made the construction of the Transcontinental Railroad possible. The railroad was built to connect the East and West coasts of the United States, and it was completed in 1869.

* Led to the development of the West: The Mexican Cession opened up the West to settlement and development. Thousands of people moved to the West in search of land, gold, and other opportunities. The development of the West had a profound impact on the United States, and it helped to shape the country into what it is today.

The Mexican Cession was a significant event in the history of the United States. It had a major impact on the country's size, population, and economy, and it helped to shape the development of the West. The Mexican Cession is still a source of debate today, and it continues to be studied by historians and scholars.