Answer:
Labour
Explanation:
The failure to find alternative sources of Labour
A historian using the historical thinking skill of examining historiography might try to determine how much has already been written about a certain subject before embarking on his or her own project, since this historiography of a topic can help you understand the evolution of "thinking about" the issue.
If the same percentage of Americans were to be killed in a war fought ... in all the other wars fought by the United States in the 19th century combined. ... the discovery of gold there in 1848, they organized a state government and .... The articles that follow focus on key aspects of the four-year conflict that not ...
Highly demanding physical labor for 13+ hours. They were payed the dirt they stood on, children were forced to miss school most of the time because they had to work to support the family. They were also highly expendable, so no medical care was offered, and they were ignored from any complaints. They were basically ignored, and couldn't do anything about it in fear of deportation of their families.
Also, racism and all that affects how they were treated.
But things like the Mexican Repatriation is something to look into. So i definitely suggest it!