Final answer:
Isa Maud Ilsen was active in the early 20th century and was interested in studying different populations. Major events in 1919, 1925, and 1926 include the signing of the Treaty of Versailles, the Scopes Trial, and the general strike in the United Kingdom.
Step-by-step explanation:
Isa Maud Ilsen was active in the early 20th century, specifically in the years 1919, 1925, and 1926.
He was interested in studying different populations and their characteristics. While no specific information is provided about the populations he was interested in, it can be inferred that he was interested in understanding social and cultural dynamics.
In 1919, several significant historical events took place, such as the signing of the Treaty of Versailles, which marked the end of World War I. In 1925, the Scopes Trial occurred, where a high school teacher was prosecuted for teaching evolution, which brought attention to the debate between science and religion. In 1926, the general strike in the United Kingdom took place, leading to widespread protests and industrial unrest.