Assuming you're referring to World War I, the main event that moved the United States from neutrality to war was the sinking of the Lusitania, since many Americans died, and it was the Germans who were responsible.
Native peoples of America had no immunity to the diseases that European explorers and colonists brought with them. Diseases such as smallpox, influenza, measles, and even chicken pox proved deadly to American Indians. Europeans were used to these diseases, but Indian people had no resistance to them.
The Great war was with Ottoman Empire
They kind of do. That is because even though a party is strong nationwide or within a state, there are high chances that their votes will almost be irrelevant because the votes will go to one of the major 2 parties. This system can discourage them from participating.
The Feudal system that had previously dominated Europe begins to collapse.
Considered divine punishment, the Black Death (bubonic plague) was one of the largest epidemics that plagued mankind.
In early 1330 the first outbreak of the bubonic plague happened in China. Plague mainly affects rodents, but their fleas can transmit the disease to people. Once infected, the infection to other people occurs extremely quickly. The plague causes fever and a painful swelling of the lymphatic glands called bulbs, hence its name. The disease can also cause blemishes on the skin that first have a reddish color and then turn black.
