Final answer:
Jewish people and Italians came to be defined as white in the United States due to a shared experience of discrimination and prejudice. Despite their regional differences, these groups came to see themselves as Italian-Americans and Jewish-Americans. Assimilation efforts and a desire for a common identity also contributed to their classification as white.
Step-by-step explanation:
Jewish people and Italians came to be defined as white because they faced similar discrimination and prejudice upon their arrival in America. Despite their regional rivalries in their home countries, immigrants from these groups realized that they shared a common struggle in the United States and began to see themselves as Italian-Americans and Jewish-Americans rather than identifying with their specific regions. Over time, US factories encouraged assimilation and the creation of a common "white" identity among immigrants and old-stock Americans alike.