Because it is more than 5,000 years old.
In reaction
to the fugitive slave law, most of the people in the north showed open defiance
to the law and devised means to support the Underground Railroad to Canada. It
is reported that they formed committees to facilitate the transport of African
American slaves to Canada through the Underground Railroad.
I believe there was a race riot in Chicago in 1919. I hope this helps
Both Andrew Carnegie Mellon and Henry Clay Frick were industrialists and business partners. Carnegie produced steel and Frick manufactured coke (necessary to produce steel). Frick eventually became chairman of Carnegie's company, but Carnegie made several attempts to force him to renounce to his position and disregarded him, and his opinions, on numerous occasions. This is, therefore, an example of the tensions that the industrialization of the U.S. entailed (there were companies that merged with, or sometimes bought, other companies; companies that used black workers and convicts as labor; companies whose workers went on strike; and hostility towards the wealthy industrialists as well as between them).
Britian because america at the time was still not powerful enough to fight it alone without the help of the french soldiers