My great-great-grandfather was Herman Ossian Armour, who, with his brother started Armour & Company (AKA Armour Meats) in 1865. My family quickly became wealthy to the point of Carnegie, Morgan, and the other "Robber Barons" of the era. While the business was sold and is no longer owned by my family, the effects of the success (and moral depravity) of the business is something that we family members still discuss among ourselves today.

While I cannot provide any specific documentation, we are aware of many situations that occurred during the course of the business that cause us distress to this day, and the work conditions (which I'm certain were beneficial to the net margins) were revolting, monstrous, and grossly unfair to everyone my family employed, in our modern, progressive eyes. Unsurprisingly, business practices were also not terribly ethical with respect to the customers, many of whom had no idea where their meat came from (e.g. US military personnel who sometimes became quite sick of not dead due to spoiled rations). While I won't repeat stories, I can say that as an insider I am certain that the working conditions were terrible, Sinclair was quite accurate, and is to this day a hero in my eyes for exposing the moral depravity of all types the Robber Barons of the era (and my great-great-grandfather). The individuals who ran many of the large businesses at the time were completely withdrawn from the affects the working conditions, and workers were a dime-a-dozen to them and barely seen as human. Worker safety and conditions in general were seen as a cost, not a requirement, and there were no organizations that supported workers in general (unions) and the federal government at the time did not interfere with most businesses no matter how many people were hurt.

My cousin wrote an article about the family business, and while the perspective of the article is from a vegan who dislikes the slaughter of animals and not the rights and safety of workers, but is still an interesting read. It should give you an idea of the thought process of the people who ran these types of businesses (my family was certainly not the only one), and affirms the lowly status of their ethical sensibilities in my eyes. With that in mind, the article can be found here:

http://www.vegsource.com/articles/armour.htm

EDIT: Oh, and I've never heard of any claim that a person was ground up in one of our plants. Could it have been possible? I guess. But I think people would still know if it really happened.

I can't answer the lard man question, but there is lots of evidence backing up Sinclair's claims about meat industry standards. Once the government caught wind of what Sinclair found during his time researching packing plants, an official investigation confirmed the claims. This in turn led to the passage of the Pure Food and Drug Act of 1906 and the Meat Inspection Act of 1906. Both acts had been proposed before but the publication of The Jungle was a major catalyst to getting them passed.

This is a quick look at how these acts were influenced by Sinclair's book.