It’s been expanded several times in the past, but it hasn’t been expanded since 1911. https://en.wikipedia.org/wiki/History_of_the_United_States_House_of_Representatives#Number_of_Representatives

The country has grown a lot. In 1911 after the last expansion, it was about 200k people per representative. We’re now close to 750k per representative. https://www.pewresearch.org/short-reads/2018/05/31/u-s-population-keeps-growing-but-house-of-representatives-is-same-size-as-in-taft-era/

I think expanding the size of congress makes sense for a lot of reasons.