The European and Asian immigrant experiences were much different during the early 20th century. One of the most significant examples were the procedures they had to go through in order to gain access to America.
For example, many Europeans came through Ellis Island (located in NY). This resulted in rounds of questioning, a six second medical exam, a citizenship like test, and mental evaluations. For Asian immigrants, they came through Ellis Island (located in San Francisco). These immigrants were subject to humiliating physical exams, that sometimes took several hours and forced them to be without clothes in front of other individuals.
European immigrants, for the most part, had a much easier time entering the US. Asian immigrants were limited based on the Chinese Exclusion Act, which suspended the immigration of Chinese immigrants into America for roughly a decade.
if this is a multiple answer quetion it will be France, Great Britain, the Soviet Union, and The United States all controlled different parts.
Making treaties and delivering the mail