The war between the U.S and mexico took place because the U.S decide they wanted to expand across the North American continent, which caused them to clash with all of it's neighbors including the british, the Mexicans and the Native Americans. Americans began migrating to the west even into land that did not belong to the United States.When Plok came into Office in 1845, he believed in the idea of "Manifest Destiny" hwich was the belief that expanding the U.S throughout the continents was both lawful and necessary.
Answer:
the black codes
Explanation:
The end of the Civil War marked the end of slavery for 4 million black Southerners. the war left them landless and with little money to support themselves. White Southerners, seeking to control the freedmen (former slaves), devised special state law codes. Many Northerners saw these codes as blatant attempts to restore slavery.
You're off by a few there lol :D Earth is actually 4.54 billion years old.