Lack of proper sanitation and nutrition and large numbers of people living in very close quarters, often with poor hygiene.
sugar plantations
Gatling guns ,cannons
The first large battle of the US Civil War was fought
they did not have enough man power
Missionaries
they stay in large groups so they can defend in large numbers.
Quantity cookery, or cooking for large groups of people.
The women of the west played a major role in settling.
Large numbers of immigrants fought in the Civil War, particularly the Irish.
This has changed over the years. Today most settle in Urban centres, usually within communities having large numbers of people from their homeland.
the pilgrams
Where did large numbers of European immigrants settle during the late 19th century
Indians and Pakistanis
The Ku Klux Klan had a very large prescence in Louisiana after the Civil War.
They break down very large numbers into groups of 3 from right to left thus making them easy to read as for example 30,000,000,000 is thirty billion
Pakistan took in millions of Indian Muslims. Great Britain also took large numbers.