Child labour refers to the exploitation of children through any form of work that deprives children of their childhood, interferes with their ability to attend regular school, is mentally, physically or morally harmful. Such exploitation is prohibited by legislation worldwide, although these laws do not consider all work by children as child labour. Child labour has existed to varying extents throughout history. During the 19th and early 20th centuries, many children aged 5–14 from poorer families worked in Western nations and their colonies alike; these children worked in agriculture, home-based assembly operations, factories and services such as news boys—some worked night shifts lasting 12 hours. With the rise of household income, availability of schools and passage of child labour laws, the incidence rates of child labour fell. In the world's poorest countries, around 1 in 4 children are engaged in child labour, the highest number of whom live in sub-saharan Africa. In 2017, four African nations witnessed over 50 percent of children aged 5–14 working.
Worldwide agriculture is the largest employer of child labour. The vast majority of child labour is found in informal urban economies. Poverty and lack of schools are considered the primary cause of child labour. Globally the incidence of child labour decreased from 25% to 10% between 1960 and 2003, according to the World Bank; the total number of child labourers remains high, with UNICEF and ILO acknowledging an estimated 168 million children aged 5–17 worldwide were involved in child labour in 2013. Child labour forms an intrinsic part of pre-industrial economies. In pre-industrial societies, there is a concept of childhood in the modern sense. Children begin to participate in activities such as child rearing and farming as soon as they are competent. In many societies, children as young as 13 are seen as adults and engage in the same activities as adults; the work of children was important in pre-industrial societies, as children needed to provide their labour for their survival and that of their group.
Pre-industrial societies were characterised by low productivity and short life expectancy, preventing children from participating in productive work would be more harmful to their welfare and that of their group in the long run. In pre-industrial societies, there was little need for children to attend school; this is the case in non literate societies. Most pre-industrial skill and knowledge were amenable to being passed down through direct mentoring or apprenticing by competent adults. With the onset of the Industrial Revolution in Britain in the late 18th century, there was a rapid increase in the industrial exploitation of labour, including child labour. Industrial cities such as Birmingham and Liverpool grew from small villages into large cities and improving child mortality rates; these cities drew in the population, growing due to increased agricultural output. This process was replicated in other industrialising countries; the Victorian era in particular became notorious for the conditions under which children were employed.
Children as young as four were employed in production factories and mines working long hours in dangerous fatal, working conditions. In coal mines, children would crawl through tunnels too low for adults. Children worked as errand boys, crossing sweepers, shoe blacks, or selling matches and other cheap goods; some children undertook work as apprentices to respectable trades, such as building or as domestic servants. Working hours were long: builders worked 64 hours a week in summer and 52 in winter, while domestic servants worked 80-hour weeks. Child labour played an important role in the Industrial Revolution from its outset brought about by economic hardship; the children of the poor were expected to contribute to their family income. In 19th-century Great Britain, one-third of poor families were without a breadwinner, as a result of death or abandonment, obliging many children to work from a young age. In England and Scotland in 1788, two-thirds of the workers in 143 water-powered cotton mills were described as children.
A high number of children worked as prostitutes. The author Charles Dickens worked at the age of 12 in a blacking factory, with his family in debtor's prison. Child wages were low. Karl Marx was an outspoken opponent of child labour, saying British industries, "could but live by sucking blood, children’s blood too," and that U. S. capital was financed by the "capitalized blood of children". Letitia Elizabeth Landon castigated child labour in her 1835 poem The Factory, portions of which she pointedly included in her 18th Birthday Tribute to Princess Victoria in 1837. Throughout the second half of the 19th century, child labour began to decline in industrialised societies due to regulation and economic factors because of the Growth of Trade Unions; the regulation of child labour began from the earliest days of the Industrial revolution. The first act to regulate child labour in Britain was passed in 1803; as early as 1802 and 1819 Factory Acts were passed to regulate the working hours of workhouse children in factories and cotton mills to 12 hours per day.
These acts were ineffective and after radical agitation, by for example the "Short Time Committees" in 1831