Answer:
there were two technological innovations that profoundly changed daily life in the 19th century: steam power and electricity. The railroad helped expand the U.S.. The telegraph, the telephone, and the typewriter brought people together that were far away.
Explanation:
It is a serious threat to Americans
After the civil war the single political entity was confirmed which led to more than four million enslaved Americans being freed. A more established federal government was also a consequence of the civil war.
the second one is the answer
