Anti-sweatshop movement refers to campaigns to improve the conditions of workers in sweatshops, i.e. manufacturing places characterized by low wages, poor working conditions and often child labor. It started in the 19th century in industrialized countries such as the United States, Australia, New Zealand and the United Kingdom to improve the conditions of workers in those countries.
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 at the same time that the slave trade (1807) and ownership of slaves (1833) were made illegal.
Ultimately, the abolitionist movement split apart. Some advocates focused on working conditions and found common cause with trade unions and Marxists and socialist political groups, or progressive movement and the muckrakers. Others focused on the continued slave trade and involuntary servitude in the colonial world. For those groups that remained focused on slavery, sweatshops became one of the primary objects of controversy. Workplaces across multiple sectors of the economy were categorized as sweatshops. However, there were fundamental philosophical disagreements about what constituted slavery. Unable to agree on the status of sweatshops, the abolitionists working with the League of Nations and the United Nations ultimately backed away from efforts to define slavery, and focused instead on a common precursor of slavery – human trafficking.