In January 1830, a debate on the nature of sovereignty in the American federal union occurred in the United States Senate between Senators Daniel Webster of Massachusetts and Robert Hayne of South Carolina. This debate exposed the critically different understandings of the nature of the American union that, by 1830, had developed between the North and the South and would ultimately lead to civil war in 1861.
Stefan Brooks examines the twin theories of union espoused by both senators against Madison's understanding of sovereignty in the Constitution, concluding that the Webster-Hayne Debate reveals the failure of Madison's characterization of the Constitution as a "partly federal, partly national" union and the futility of dividing sovereignty between the United States government and the states. This division of sovereignty represents a defect of the Constitution, an understanding of which helps to explain the collapse of the union into civil war in 1861.