Which plan introduced by James Madison proposed a bicameral legislature with representation based on population size?

The Virginia Plan introduced by James Madison proposed a bicameral legislature, meaning it consisted of two separate chambers. This plan called for representation in both chambers to be based on the population size of each state. The more populous states would thus have greater representation, which reflected the interests of larger states in shaping national policy. This approach was part of a broader movement towards a stronger central government, recognizing the need for a federal structure that could effectively manage the diverse interests of the thirteen states.

In contrast, the New Jersey Plan sought to maintain equal representation for all states regardless of population, reflecting the interests of smaller states. The Connecticut Compromise later blended elements from both the Virginia and New Jersey Plans to establish a fairer representation system that balanced the needs of both large and small states. The Northwest Ordinance, while significant in its own right for governance and statehood in the northwest territory, did not address the structure of the legislature itself. Thus, the Virginia Plan is correctly identified as the proposal that emphasized representation based on population size.