Obviously the poor had no money, so the bosses of say New York would pay clueless immigrants to vote for them in elections to keep them in high city offices and to continue holding power.
It closed down all trade routes to Asia.
If the plague, also referred to as ''black death'', didn't occurred in Europe, the continent would have had a much larger population for starters. Because of the plague and the huge loss of population, Europe faced huge problems from social, economic, and military perspective, but if it hadn't occurred, Europe would have been much stronger and the progress of the continent would have been evident and bigger earlier in time. Considering the European colonialism, it was also going to have a huge global effect because there was going to be a much larger number of people migrating into the European colonies later on.
The introduction of the cotton gin by Eli Whitney had a great effect on the plantations, as well as slavery. Before the cotton gin was invented, the production of cotton was a… painstaking business. To remove the cotton fiber from the seeds took a great amount of time.
"Yellow Journalism" was largely responsible for swaying popular support of sensationalizing headlines and questionable facts.