What was john c calhoun’s theory of nullification

Prior to the presence of europeans on the continent, the slave trade in africa a) did not exist in any form. b) was limited to internal trade only. c) included the trans-saharan and indian ocean slave trade. d) was rarely needed due to the lack of an agricultural economy.

How did the governor's order that only georgian officers could command georgia's troops demonstrate a problem in the south

Which act of the conquistador pizarro was crucial in overthrowing the inca? a. the destruction of the ancient inca city, machu picchu b. the siege of the inca capital near the cuzco valley c. the execution of the last inca ruler, atahualpa d. the unexpected deaths of 3 million inca warriors e. the murder of former inca emperor, huascar