The Article of Confederation did not work well. Congress had the power to make rules. However, it had no power to demand funds (only request) from the states. It had no enforcement power and could not regulate commerce or print money.
In May 1787, through the hot summer, and until September 17, rancorous arguments erupted about nearly everything within the shuttered windows of the State House. With delegates sworn to secrecy, the citizens of the new republic waited for news. European nations waited for the collapse of the American experimental government.
What emerged was a document so radical that it was not sent to the state legislatures to ratify, because it required states to give up some of their power, and that never would have passed. Instead, special ratifying conventions were convened in each state. Even then, only 6 states were willing to ratify it. Massachusetts, the last state needed, agreed to ratify the Constitution only with the agreement that it would be amended later. It was with the Bill of Rights.
Some changes were a stronger central government which could regulate commerce, print money, and enforce their laws. It was limited strictly to the list of powers within the Constitution. All branches of the government were equal and ways to balance this were described. The election to congress was a balance between democracy (the House was elected directly by the people) and a republic (senators were nominated by state legislature!)
The argument that is still talked about today, was the disagreement regarding how many House representatives each state should have. The constitution stated one representative for every 30,000 people. The term “people” had been used throughout the Constitution, but in this instance, it translated directly into POWER. Southern states, as can be seen in the excised Jeffersonian section, held the world understanding that, of course, slaves were also “people of the United States.” (Notice, the Constitution does not say Citizens of the United States anywhere except for the members of the central government.) Northerners, determined to limit southern power, refused to count slaves in the assignment of representatives.
The final compromise was to count each slave as 3/5 of a person—but note that it was the northern states that denied personhood to slaves.
That is not what we have been taught.