Engineers, who were the leaders of the Underground Railroad, helped slaves who were running away by providing them with food, shelter, and sometimes jobs. They hid the slaves from people who were trying to catch them and return them to slavery.
The GDP per Capita, in Nigeria, when adjusted by Purchasing Power Parity is equivalent to 32 percent of the world's average.
As a result, its GDP per capita is only $57,300. That makes it the 18th most prosperous country per person. China has the largest GDP in the world, producing $21.2 trillion in 2016. But its GDP per capita was only $15,400 because it has four times the number of people as the United States. It's the most populous country in the world, with 1.37 billion people. The European Union is the world's second most prosperous economy, at $19.2 trillion.