Wanted strong national government
The amount of territory the US currently has would have been completely different if the national government could only legislate based on what is written in the constitution.
A perfect example of this is the power to purchase land/territories from other countries. This was first done by Thomas Jefferson with the Louisiana Purchase of 1803. The US Constitution does not say that the president has the power to buy land from other countries. However, Jefferson said that this power was "implied" by the Constitution.
This idea of an implied power greatly changed the presidency/national government. Several presidents after Jefferson would follow his lead by making deals with countries for territory.
If it wasn't for this concept of implied powers, the US may not have grown to the 50 states we know it as today.
Food, Residence, and Water
The main attraction was the possibility of having slaves, since the owners of farms needed cheap and very abundant labor. Precisely this great attraction of owning slaves and being able to cultivate enromes quantities of land, was what would lead to the American Civil War; being the slavery, the first reason of the great growth of the southern wealth, thanks to its enormous plantations of cotton and tobacco; but after the war, this was the reason why the southern states suffered economic crises and had to request loans from the Federal Government for reconstruction; also that the very loss of the slaves led to the economic problems of the South.