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.
US GDP as % of World GDP: US GDP as % of World GDP is at 24.32%, compared to 22.12% last year. This is lower than the long term average of 29.39%. US GDP as % of World GDP Chart.