I want to know the answer to the following question:
Why were there more immigrants in the US?
All the background I'm provided with is that "By 1990, the Census Bureau included more than a dozen ethnic/racial categories on the census, reflecting not only changing social ideas about ethnicity, but the wide variety of immigrants who had come to reside in the United States due to changing historical forces and new immigration laws in the 1960s.". Is that enough to answer the question?
Answer: yes