Redrawing Democracy: Quantifying House District Continuity and Change, 1789-2024

How have U.S. House districts changed since the Founding? When do mapmakers reshape districts - and when do they choose to preserve them? This article introduces the concept of 'spatial protectionism' - the strategic minimization of district change - and develops four original measures to analyze redistricting changes from 1789 onwards. I demonstrate how the strategic imperatives, racial context, and technical capabilities of mapmakers shape the magnitude and form of district change across five redistricting eras: Spatial Representation, Shifting Apportionment, Relative Stasis, Racial Redistricting, and Precision Engineering. My analysis reveals persistent low change disrupted by shifts to at-large districts; unprecedented boundary changes in the last decade; and clear associations between racial demographics, party control, and patterns of continuity and change. These findings establish the first empirical standard for judging the magnitude of district change and underscore the dual significance of stasis and dynamism in the politics of redistricting.