What was the colombian exchange and how did it effect the native americans and europeans?

What was the purpose of the u. s navy's convoy system

What is the main idea of this excerpt

What does the country say concerning the status of free blacks living in the united states? a) they have the same rights as any other "free" people, and are full citizens. b) they have the same rights as any other "free" people, but are not properly citizens. c) they are citizens, but don't have the full rights granted to other citizens. d) they are not citizens, and have no right to petition the court.