Because of the different beliefs on how a country is run also u.s dropped 63500 tons of bomb in Korea
Normally, during the agricultural revolution before there would be a population spike because children were valued for farm labor and there was a decline during the industrial revolution because children were not valued in the work force like in factories and cost lots more money to take care of.
However, if there was a spike in the population during the industrial revolution it would probably be because people had more kids to go out and work in the family business or go out and work in the factories which mean they were valued in the work force...
The Soviet Union (The USSR)