A good word for the particularly insidious efforts of child labor at the time. To encroach:"to enter by gradual steps or by stealth into the possessions or rights of another." Thank you Merrian Webster. Word Origin information includes "The history behind "encroach" is likely to hook you in. First appearing in English in the 16th century, the word derives from the Middle English "encrochen," which means "to get or seize." The Anglo-French predecessor of "encrochen" is "encrocher," which was formed by combining the prefix en- ("in") with the noun "croche" ("hook"). "Croche" also gave us our word crochet, in reference to the hooked needle used in that craft. "Encroach" carries the meaning of "intrude" both in terms of privilege (as demonstrated in our first example sentence) or property (as in our second example sentence). The word can also hop over legal barriers to describe a general advancement beyond desirable or normal limits (such as a hurricane that encroaches on the mainland)." [https://www.merriam-webster.com/dictionary/encroachment]