Why was child labor so popular during this time period (1877-1914)?

Hello! well in my opinion 1865 is when the slaves became free therefore they had no one to do there jobs for them like tend to there crops or work in there factory there were over 1.4 million slaves  but they say On that day, 250,000 but they were way more therefore some were to old to work that's were child slavery aka child labor came in.

Explanation:

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