D) Increased immigration in industrial areas.
By 1890, production by factories in American had grown eight times larger than what it had been before 1860. A large part of the workforce came from immigrants coming to the United States and settling in cities, looking for jobs. Ireland was one example of a country from which many immigrants came, looking for work in America, after the devastation of famine in Ireland (especially from potato crop failures).
National blue and corn gold are adopted as FFA colors. Also Carlton Patton from Arkansas is named the first star farmer of America. This is one of the first awards created by FFA and it was sponsored until 1949 by the Kansas City Star.
Andrew Carnegie was an American industrialist who amassed a fortune in the steel industry then became a major philanthropist. Carnegie worked in a Pittsburgh cotton factory as a boy before rising to the position of division superintendent of the Pennsylvania Railroad in 1859.
The answer is Iron because the Iron Age lasted roughly from 1500 BCE to 500 BCE.
