Becoming "white" in America

by RunRunDie

In early 20th century America, people of Irish and Mediterranean descent were not considered "white". This suggests that "whiteness" is not directly related to skin pigmentation or being of European descent.

What steps did those groups have to make in order to become "white"?

What is the consensus among historians as to what American society considered to be "white" at that time?

Assuming "whiteness" is not directly connected to pigmentation or ethnicity, are other traditionally "non-white" groups in the process of becoming "white" (keeping in mind the 20-year rule), such as East Asians?

Searocksandtrees