It was born out of political disagreements on how to distribute votes. The small states repeatedly threatened to quit the convention if they were forced to operate under proportional representation in the federal government, and since (in theory), the small states had the majority of votes in the convention, they could deadlock it on occasions. As such, a series of weird and sometimes insane ideas were put forward, amongst which were plans to create blocks of states which would all have equal votes, as a middle ground between the two ideas. It didn't end up, because people like Roger Sherman, and Benjamin Franklin devised the system the USA uses today. But, if they failed, and the block idea somehow got into the forground, it might be the operating principle of the USA's legislature.