You would be surprised to learn that almost 69% of the US mushroom production occurs in the borough of Kennett Square, Pennsylvania. It is a small town of about 6000 people, but mushroom-growing facilities around town produce almost 451 million pounds of mushrooms annually (2024). 451 million pounds of mushrooms would occupy about 45 American football fields or 35 soccer fields. The dollar value of mushroom production in the US is roughly $ 1 billion per year.

China is the undisputed leader in mushroom production. China accounts for 93% of the world’s global mushroom production.

That is from Rhishi Pethe, here is the full story, via Anecdotal.  Much of the piece is about why mushroom production is switching to Canada.