The Jungle is fiction. Congressional studies at the time showed that it was not an accurate depiction of conditions, but major meat packers were able to use it as an excuse to push their quality control expenses onto the taxpayers. Even Upton Sinclair himself opposed the resulting legislation. He said that the true purpose of his NOVEL had been to result in higher wages, NOT increased regulation, and especially NOT the cronyistic regulations that resulted. https://www.zeroaggressionproject.org/uncategorized/upton-sinclairs-the-jungle/