- Germany and Italy. -
Neither became independent,sovereign nations until the second half of the 19th century (1861 and 1871 respectively). Neither had a powerful navy when they became unified,so it took time to build up both a sufficiently large surface fleet and merchant marine to make imperial acquisitions overseas viable and defensible. A combination of these factors meant that,by the time both were ready and eager for imperial colonies in Africa,much of the continent (and certainly all the best bits) had long since been claimed by others.
The triangular trading system was not only used to sell/buy slaves, many countries benefitted from other resources that were scarce in their lands. The thirteen colonies would trade fish, whale oil, lumber, tobacco, rum, iron products, flour and meat products and England and Europe would trade teas, spices, furniture, cloth, tools, iron products, etc. New England specifically would trade with the Caribbean for sugar (or molasses) and New England would distill it into rum. The profits from the sale of the sugar would be shipped to West Africa where the majority of slaves came from, and the slaves were sent to the Caribbean to work on sugar plantations.
B because freedmen were unable to vote due to black codes
Hunters and gatherers were mainly scavengers and lived off of what they could find and agricultural communities could grow their own food and also sell it for a profit with no worries. Hope this is right! :)