1906 is the same year The Jungle was published, a story that sparked interest in the quality of the meat industry in America. If your meat was more processed, the worse it would be. Boneless canned chicken is probably just a bunch of meat scraped off the parts nobody wanted to eat, maybe even a few pars from other animals, or humans if there was an accident that day.

If I had to guess...

https://en.wikipedia.org/wiki/The_Jungle

Published Feb, 1906.

However, the novel's most notable impact at the time was to provoke public outcry over passages exposing health violations and unsanitary practices in the American meat-packing industry during the early 20th century, which led to sanitation reforms including the Meat Inspection Act.

The conflict begins a week earlier when the health department labels 50,000 pounds of canned chicken at the North American company and the A. Booth & Co. as suspicious. The health commissioner does not take long to arrive at a conclusion, noting that when samples were thawed out the smell “was so nauseating it was necessary to drench them with formalin before they could be handled.”

http://www.connectingthewindycity.com/2017/10/october-2-1906-north-american-cold.html?m=1