What was the main issue of concern in the 1800s between the federal and state governments?

i believe the answer is d.

the group i'm selecting: greeks.

a first group of greek immigrants came to the us in the 1850s. the second group came to america starting in the 1890s due to economic opportunities they didn't have back in their home caused by the hardships of ottoman rule. greek immigration was 90% male, many of them expected to work and return to greece after earning enough capital, but ultimately had to remain in the us after the greek genocide.

an era of negotiation.

is that an answer to your question?

c. free trade can lead to low pay for workers in poorer countries.