Some of the earliest sweatshop critics were found in the 19th century abolitionist movement that had originally coalesced in opposition to chattel slavery, and many abolitionists saw similarities between slavery and sweatshop work. As slavery was successively outlawed in industrial countries between 1794 (in France) and 1865 (in the United States), some abolitionists sought to broaden the anti-slavery consensus to include other forms of harsh labor, including sweatshops. As it happened, the first significant law to address sweatshops (the Factory Act of 1833) was passed in the United Kingdom several years after the slave trade (1807) and ownership of slaves (1833) were made illegal.
