A meeting that was held in Philadelphia made fifty delegates to meet together and decide to replace or modify the articles of federation which was considered to be weak and ineffective.
Articles of confederation placed undue powers to the states, it was empowered to impose taxes and execute laws which made the central Government to be ineffective. The states were apprehended regarding the replacement of Articles of federation.
The Great compromise led to the equal representation of all states in the congress. It was decided that the lower chamber (House of Representatives) be formed based on the representatives sent from the states with larger populace and the senate be formed by the representatives sent from the smaller states.
Now the debate revolved around the topic of slave representation that were not considered as subjects and not given the rights to enfranchise, so the great compromise concluded that three of five slaves would be counted as a subject in order to draw the estimate of population.