Which major u.s. region was mostly avoided by non-anglo voluntary migrants throughout the nineteenth and most of the twentieth century?

Not  Pacific Coast or Midwest

Explanation:

The majority of the non- Anglo migrants throughout the 19th and 20th century were avoiding the West and Pacific Coasts because they were looking for the jobs, not for land. Majority of the immigrants came from Central, Eastern and Southern Europe. They all worked in the industries on the East side of America to earn a living to start a new life. Between 1880 and 1920 the country saw rapid industrialization and urbanization.  

Europeans had advanced farming methods, tools, and more powerful weapons.This shows that when a certain population overpowers an existing population in a terrain/land the assailant has powerful technology than the latter.