The best example of a major dispute during the Constitutional Convention is the Virginia Plan vs. the New Jersey Plan.
The Virginia Plan, proposed by James Madison, called for a strong national government with a bicameral legislature based on population. In contrast, the New Jersey Plan, proposed by William Paterson, emphasized the sovereignty of the states and sought to maintain the structure of the Articles of Confederation, proposing a unicameral legislature with equal representation for each state. This disagreement between the two plans was a significant point of contention that ultimately led to the Great Compromise (Connecticut Compromise), which established the current structure of Congress comprising both the House of Representatives and the Senate.