This cartoon from 1921 shows several people from different ethnic groups that appear to represent immigrants to the United States in the 1920s. Through some rough searching of distinctive clothing from the 1900s I think that the ethnicies are, from left to right:

1: African, probably east-central

2: Greek

3: Jewish

4: Italian (Venetian)

5: Russian

6: Cossack (Slavic)

7: West Asia/Punjabi

8: Chinese

Am I completely off the mark?

Source: Thomas Guernsey Moore (1874-1925) Uncle Sam, 1921 Illustration for “The Comedy of Americanization” by Katharine Fullerton Gerould in The Saturday Evening Post v. 194 # 18 (October 29, 1921).