Problems america faced as more and more people emigrated from diff nations

Between the beginning of the decade of 1780, at the end of the War of Independence, and 1914, at the outbreak of the First World War, the United States went from being a country with a small population, distributed over a large territory, to be the nation with the highest per capita income in the world and the leading industrial country, surpassing Great Britain since the late nineteenth century. Between 1896 and 1900, the United States generated 30% of world industrial production, while in that period, Great Britain was responsible for 20%, and Germany, 17%.

The US had an extraordinary increase in population, which went from less than 4,000,000 inhabitants in 1790 to 90,000,000 in 1910, thanks to massive immigration. This population increase, produced a large number of problems in the population, in principle there were no houses for all people who came to the country, so the collective housing arose, in which several families lived, this added to the deficient services, such as be the health and health services, which over time were improving.

climate change is the big reason to the decline of the indus valley which also caused floods. so i dont know what answer would best fit the description thats just what i found online! have an awesome