The Apportionment Act of 1911 set the number at 435. The 1929 Act established the process for allocating seats after a census. This was made automatic in 1943.
I’m curious about actual contemporary arguments for and against setting and keeping that limit ca. 1900 to 1955 (or earlier, if anyone knows about the 1843 decrease.) What were they? Was it at all contentious? Angry debates on the Hill? Rants in newspapers? It’s possible we won’t find much of anything. 435 was sort of a status quo number at the time, and we (mostly) stopped adding states. I’m guessing that most previous increases roughly kept the number of reps from old states constant while adding seats to new states. But I haven’t actually checked each year yet.
I’m not interested in modern arguments for more or fewer reps, which we see from time to time, nor in actually arguing the number.