Principles of Politics Exercise

Goals of This Exercise

  • Examine the instrumental reasoning behind the Three-fifths Compromise during the Constitutional Convention.
  • Illustrate the “southern advantage” in representation from 1790 to 1820 that resulted from the Three-fifths Compromise.
  • Explore how this and other constitutional “rules” matter for political outcomes.

The Three-fifths Compromise

  • What was it? The Three-fifths Compromise held that three of every five slaves would count as “population” for the purposes of apportioning seats in the House of Representatives.
  • Who advocated it? Southern states, where over 90 percent of slaves in America lived, with slaves having “constituted about 30 percent of the population of the region”.*
  • Who opposed it? Northern states, where very few slaves resided.

*Donald L. Robinson, Slavery in the Structure of American Politics, p. 4

Examining the Rationality Principle

The Rationality Principle: all political behavior has a purpose. All political actors engage in instrumental acts to further their goals.

Southern States

Argument: Slaves should count fully toward the apportionment of House seats.

Northern States

Argument: Because they could not vote and were not citizens, slaves should not count toward the apportionment of House seats.

Answer the following question:

What was the instrumental reasoning behind the arguments in support of and in opposition to counting slaves in the apportioning of seats in the House of Representatives?

The Results of the Three-fifths Compromise

  • The South would get a representation “bonus” disproportionate to its free population but the non-Southern states would retain majority control of the House of Representatives.
  • Not only did the Three-fifths Compromise matter for the initial apportionment of House seats, but the Southern states believed that they would continue to accrue benefits over time, as the continued importation of slaves meant that the three-fifths rule, once established, would increase their House representation and offset non-slave population growth in the Northwest.

South and Non-South Representation 1790

South and Non-South Representation 1820

Number and Percentage of House Seats for Southern States Due to Three-Fifths Rule

Examining the Policy Principle

The Policy Principle: political outcomes are the products of individual preferences and institutional procedures.

As a constitutional procedure, the three-fifths rule had important consequences. Every law that passed the House of Representatives was “filtered” through the representation “bonus” the three-fifths rule afforded the South.

Answer the following questions:

2. How many “extra” House seats did the South get as a result of the three-fifths rule in 1790? In 1800? In 1810? In 1820?
3. What advantages did the three-fifths rule give the South in national policy making?
4. What advantages did the three-fifths rule give the South in presidential elections?

Examining the History Principle

The History Principle: how we got here matters, and historical outcomes are “path dependent”; that is, prior decisions and rules affect the outcomes that follow.

The Three-fifths Compromise established a historical “path” that had continuing consequences:

  • The Presidential Election of 1800: Thomas Jefferson defeated John Adams with 73 electoral votes to Adams’s 65 electoral votes. Inasmuch as 53 of Jefferson’s votes came from southern states and only 9 of the Adams votes were southern, the South’s “bonus” representation in the House accounted for Jefferson’s presidential victory in 1800.
  • The Louisiana Purchase: Once elected president, Jefferson negotiated the Louisiana Purchase, which increased the amount of southern land where slavery could thrive. The purchase itself was a partial result of the “southern bonus” in the House which, in turn, further increased southern strength in the House.
  • Any future effort to repeal the “federal ratio” set by the Three-fifths Compromise likely would have to be approved by the House, which was disproportionately southern because of both the three-fifths rule and the Louisiana Purchase.

Answer the following question:

5. How do rules, particularly rules about apportioning representation, perpetuate themselves?


  • Robinson, Donald L. Slavery in the Structure of American Politics, 1765–1820. New York: Harcourt Brace Jovanovich, 1971.
  • Stanley, Harold W., and Richard G. Niemi. Vital Statistics in American Politics, 1997–1998. Washington, DC: CQ Press, 1998.
  • Wills, Gary. “Negro President”: Jefferson and the Slave Power. New York: Houghton Mifflin, 2003.

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