Who served first as secretary of state, then as supreme court justice?

What was eleanor roosevelt's most significant achievement?

Which event to improve foreign relations between the united states and china?

What is the columbian exchange? o a. the changes that resulted from europeans settling in the new world b. the relationships that columbus and his men had with the natives they met o c. the ships that columbus bought with money from the king and queen of spain o d. the increase in the number of native american towns in the new world