Answer:
In the 1800's. If you wanna be really specific, it's the late 1790's.
The Triangle Trade brought labor for a <em>very</em> cheap price, much much cheaper than indentured servants. They also began to use the triangle trade instead of enslaving the locals because the natives knew their way around the land and could run away easily.
The delegates agreed they needed a national government. But they were afraid of making one that was too strong. They believed that most of the powers of government should be kept by the states because citizens could control state governments more easily than they could control a national government.
C. Inevitable
They were going to need to expand any way because they were running out of room on the East coast
