It meant that as soon as one country falls under communist control, another country would fall and so on. Vietnam at the time was split into North (communist) and South (being attacked by North) and the US didn't want communism to spread, reasoning that it might eventually come to the US if nothing was done.
The last battle is the answer :)
Answer:
Philip Danforth Armour
Explanation:
He founded the meatpacking company "Armour and Company" in Chicago in 1867, which matches the American businessman and 19th century parts of your question. I hope this helps!
Answer:
world saw a major increase in population
Explanation: The Industrial Revolution impacted the environment. The world saw a major increase in population, which, along with an increase in living standards, led to the depletion of natural resources. The use of chemicals and fuel in factories resulted in increased air and water pollution and an increased use of fossil fuels.