I am pretty sure that it is the early 20th century
South Africa, which is in Africa :)
"American purity is being harmed by the immigration of non-Anglo-Saxon people."
The United States was the only country that was not under imperial control during this time. The US was becoming the largest economy in the world. It was becoming the largest military in the world, more so than Great Britain.
who was the founder of the early 19th and late 20th century diplomatic alliance
In the late 19th century and early 20th century
Question is not clear, but she lived in early and mid 20th century.
late 19th to early 20th century
Those who favored American imperial expansion in the late 19th and early 20th century believed it would provide bases for the U.S. Navy.
in the early 20th century. It couldve also been in the late 19th century.
The Industrial Revolution ended between the late 19th century and early 20th century.
It was first discovered by accident in the late 19th century, but was not used until the early/mid 20th century.
It allowed more room for cities to grow