Question

Once the Constitution was approved, what more had to happen before it could go into effect?

Answer 1

By approval, I think you mean by the delegates from each state had approved it. The problem was that the states themselves had to approve it. That seemed like a cumbersome process, but you have to remember that democracy works on the will of the people and each state had to ratify it keeping in mind that there were still problems: it was not a slam dunk.