The sea journey undertaken by slave ships from West Africa to the West Indies.

What do the discoveries of shells used in jewelry and a huge dredged canal tell us about the indus valley civilization?

Which phrase best completes the diagram?

The telegraph, the transatlantic telegraph cable, and the telephone were important to businesses after 1850 because of a. they created a system for developing new inventions. b. they filled a need that other inventions of the day could not. c. they attracted investors and created the stock market. d. they made picture-taking a popular american pastime.