Maps
Interactive maps built for research and for teaching — congressional redistricting and House apportionment, the equal-area cartograms that redraw every district at the same size, and write-ups of how those cartograms are made.
Mid-Decade Congressional Redistricting
Interactive map of mid-decade congressional redistricting: which states have redrawn their maps, which are blocked or proposed, and the expected partisan seat shifts.
Open the map →U.S. House Election 2022 Cartogram
The 2022 U.S. House results on a cartogram that rescales each state to its seat count and splits it into equal-area districts, morphing to and from the geographic map. Built with mapshaper and base R.
Open the map →Projected change in U.S. House apportionment, 2020 to 2030
13 seats would move between 16 states. Every state is drawn at its peak seat count and split into equal-area cells, with the seats that moved marked. Built with mapshaper and base R.
Open the map →Change in U.S. House apportionment, 2010 to 2020
7 seats moved between 13 states. Every state is drawn at its peak seat count and split into equal-area cells, with the seats that moved marked. Built with mapshaper and base R.
Open the map →Change in U.S. House apportionment, 2000 to 2010
12 seats moved between 18 states. Every state is drawn at its peak seat count and split into equal-area cells, with the seats that moved marked. Built with mapshaper and base R.
Open the map →Cartogram studio
The equal-area U.S. House cartogram, solved live in the browser. Change the state size, the padding between states, the seat counts or the sample size and watch the placement, carving and assignment re-solve.
Open the map →Alpine Lake — New Construction Over Time (1970–2025)
Every parcel in the Alpine Lake tax district (Preston County, WV) animated from 1970 to 2025, lighting up in the year its home was built, from county tax assessment records.
Open the map →