The 1920 census is when things broke down. For the first time, a majority of the population lived in “urban” areas. And although the Census Bureau’s definition was broad — it included any place with at least 2,500 people — the finding reflected America’s power center was moving away from rural areas toward urban ones due to industrialization and high levels of immigration from Southern and Eastern Europe. This made the apportionment process particularly challenging, as Congress had to navigate two competing concerns: first, the worry that greater urban power would lead to rural seat loss if the House didn’t expand, and second, a growing belief among many members that the House was already too crowded and that an increase in seats would make it truly unwieldy.

Nevertheless, the Republican chair of the House Census Committee put forward legislation in 1921 to increase the size of the House by 48 seats — 483 in total. Once again, this would have prevented any state from losing a seat, a politically attractive option.5 But this time both parties were deeply divided over expanding the House, with arguments that adding seats would be too expensive or hinder legislative functions.

Congress tried a number of alternatives. First, the House passed an amended bill to keep the House at 435 members. Eleven states stood to lose seats as a result, and unsurprisingly many senators from those states worked behind the scenes to keep that bill from ever getting a vote in the Senate. Next, the House tried to expand to just 460 seats instead of 483, which would have caused only two states to lose a seat, but that narrowly failed by four votes on the House floor. This left Congress at an impasse, and over the next few years, reapportionment stalled.