Federalism is a mixed or compound mode of government that combines a general government with regional governments in a single political system. Its distinctive feature, first embodied in the Constitution of the United States of 1789, is a relationship of parity between the two levels of government established.
In short, the Colonial system of indentured servitude (working for 5-7 years for someone to pay them back for your trip across the Atlantic) was running out of people. So the British brought African peoples across.
