Elected as a Whig congress in 1846, Lincoln gained notoriety when he lashed out against the Mexican way, calling it immoral, pro slavery, and a threat to the nations republican views
Mexico has been involved in numerous different military conflicts over the years, with most being civil/internal wars.
China was surrounded to the west by mountains and deserts. These geographical features kept China isolated from the rest of the world, allowing its civilization to flourish in isolation from Europe and the rest of the world until the development of the Silk Road.
driven by economic ambitions and a sense that the United States was “destined” to span the entire continent, the war also raised the issue of how acquisition of such a large territory would affect the balance between slave and free states.