Although the southern states were all seated in Congress by 1870, federal troops remained in some southern states until the compromise of 1877. * true or false

True.

Explanation:

The exit of Union troops from the territory of Southern states marked a symbolic end to the Reconstruction Era. It followed a major political deal between Republicans and Southern Democrats. The 1876 election was a disputed election; results from Louisiana, Florida and South Carolina - three states where Republicans still governed  - were questioned. The deal recognized the victory of Republican Rutherford Hayes as president and agreed to Democratic control in the South.

In the 1870s, the Republican Party had turned more conservative and less egalitarian, and though the 14th and the 15th Amendments had been passed by Congress to give rights to African-Americans, Southern legislatures had passed laws that put important barriers to the African-American voters to exercise their rights.

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