Describe the social impact of industrialization on workers and cities, and explain how capitalism, socialism, and Marxism emerged as competing responses to those conditions.
Factory towns like Manchester and Liverpool grew explosively, often faster than anyone planned for: workers crowded into cheap housing with no sewers or clean water, and diseases like cholera swept through neighborhoods with terrifying speed. Inside the mills and mines, conditions were often brutal -- children as young as five or six worked twelve- to fourteen-hour days, sometimes crawling into narrow spaces beneath machinery too dangerous for adults. In 1832, a British parliamentary committee led by Michael Sadler collected testimony from mill workers themselves; one teenager described being beaten to stay awake near the end of a shift that had started before dawn. That testimony helped push Parliament toward the Factory Act of 1833, which limited child labor ages and hours, and the Mines Act of 1842, which banned women and children from working underground -- early, halting steps toward the labor protections taken for granted today.
These harsh conditions did not go unanswered. Adam Smith's The Wealth of Nations (1776) had already argued that free markets, left alone by government (laissez-faire), would efficiently organize an economy as if guided by an "invisible hand" -- the reigning economic idea of the age. Reformers like Robert Owen tried a different approach, building a model factory town at New Lanark, Scotland, with better housing, education, and shorter hours, to prove humane treatment and profit were not opposites. The most influential response came from Karl Marx and Friedrich Engels, whose Communist Manifesto (1848) argued that "the history of all hitherto existing society is the history of class struggles" between the bourgeoisie (owners) and the proletariat (workers), predicted this struggle would end in a workers' revolution, and closed with the rallying cry, "Workers of the world, unite!" Meanwhile, ordinary workers pursued a less revolutionary path: organizing labor unions to bargain collectively for better wages and conditions, even though such organizing was illegal in Britain until 1824.
Mastery looks like: They can describe at least two real hardships of early industrial labor with specific evidence, and explain the core difference between Marx's revolutionary socialism and the labor-union/reform approach.
Common stumbles: Discussing industrialization's costs only in vague terms ("it was hard") instead of citing specific documented conditions, or treating Marx's ideas as simply "communism is bad" without engaging with the actual argument he made about class struggle.