Visualizing Temporal Patterns in the United States Supreme Court’s Network of Citations

The above image is a visualization of temporal citation patterns in the history of the United States Supreme Court.  Each case is placed horizontally across the image in chronological order.  We then draw citations between cases as curved arcs.  We use three distinct arc colors to show qualitative differences between these citations:

  • RED arcs correspond to citations within a natural court (e.g., the Rehnquist court citing the Rehnquist court).
  • GREEN arcs correspond to citations from one natural court to the previous natural court (e.g., the Rehnquist court citing the Burger court).
  • BLUE arcs correspond to citations from one natural court to a natural court prior to the previous natural court (e.g., the the Rehnquist court citing the Marshall court).
  • Note that yellow is produced when red and green overlap.

Though there are many ways to interpret this data, we wanted to provide three simple conclusions to draw:

  1. The number of cases decided within each natural court varies dramatically.  For instance, the Rehnquist court decided fewer cases than the Fuller court.
  2. Most citations are to recent cases, not cases in the distant past.
  3. The Burger and Rehnquist courts rely heavily on cases from the Hughes, Stone, and Vinson courts