Unit 6 covers c. 1815 to c. 1914 and rests on three claims the CED states as key concepts:

• The Industrial Revolution spread from Great Britain to the continent, where the state played a greater role in promoting industry.
• Everyday experience was shaped by industrialisation depending on the level of industrial development in a particular location - so the answer to "what was life like" is always where, and how far along.
• Political revolutions and the complications of industrialisation triggered a range of ideological, governmental, and collective responses 意识形态、政府与集体回应.

That third claim is the unit's spine. Industrialisation created problems; the ideologies and reforms of the nineteenth century are the answers people proposed to them.

Britain led, and the CED gives the reasons as a set:

• Ready supplies of coal, iron ore, and other raw materials.
• Mechanisation of textile production, iron and steel, and the development of machine tools.
• Economic institutions and human capital 人力资本 - engineers, inventors, and capitalists.
• A parliamentary government that promoted commercial and industrial interests because those interests were represented in Parliament - the political condition, and the one students leave out.

The continent then diverged, which is the examinable comparison:

• France industrialised more gradually, with government support and with less social dislocation 社会失序 than Britain.
• Elsewhere, a combination of geography, lack of resources, the dominance of traditional landed elites, and the persistence of serf-like labour relations slowed industrialisation.
• Because more primitive agricultural practices and landholding patterns persisted, some areas of Europe lagged behind entirely.

By 1914 mechanisation and the factory system had become the predominant modes of production. During the second industrial revolution 第二次工业革命 (c. 1870-1914) industrial activity spread across more of Europe, and:

• New technologies and means of communication and transport - notably railroads 铁路 - produced more fully integrated national economies 一体化的国民经济.
• Efficient transport and other innovations created new industries and improved the distribution of goods.
• Together with better harvests from the commercialisation of agriculture, industrialisation promoted population growth 人口增长.
• A heightened consumerism 消费主义 developed.

• In industrialised western and northern Europe, socioeconomic change created divisions of labour leading to an entrepreneurial and professional middle class and an industrial working class.
• In less industrialised areas, the dominance of agricultural elites continued into the twentieth century.
• Class identity 阶级认同 developed and was reinforced through participation in philanthropic, political, and social associations.
• Rural-to-urban migration produced urban overcrowding 城市拥挤 while affected rural areas suffered population loss.
• Bourgeois families focused on the nuclear family and the cult of domesticity 家庭崇拜, with distinct gender roles.
• By the century's end, higher wages, laws restricting the labour of children and women, social welfare programmes, and improved diet raised living standards.
• Economic motives for marriage diminished as the middle-class notion of companionate marriage 伴侣式婚姻 spread.
• Leisure time centred increasingly on the family or small groups, with new activities and spaces built for it.

The Concert of Europe 欧洲协调, or Congress System, sought to maintain the status quo through collective action and adherence to conservative principles.

Conservatism 保守主义 in this period is a genuine ideology, not merely resistance: it supported traditional political and religious authorities on the ground that society is an organic whole with a natural hierarchy, which cannot be redesigned by abstract reason without harm.

In the first half of the nineteenth century, revolutionaries attempted to destroy the status quo. The revolutions of 1848 1848年革命, triggered by economic hardship and discontent with the political order, challenged conservative power across Europe - and largely failed, which is itself examinable.

In Russia, autocratic leaders pushed through reform and modernisation from above, including the emancipation of the serfs 农奴解放 - reform used as an alternative to revolution rather than a concession to it.

The CED names five positions, and they are best learned as answers to one question: who should hold power, and what should the state do?

• Liberals 自由主义者 emphasised popular sovereignty, individual rights, and enlightened self-interest, but debated how far all groups should share political power.
• Radicals in Britain and republicans on the continent demanded universal male suffrage 男性普选权 and full citizenship without regard to wealth.
• Socialists 社会主义者 called for the redistribution of society's resources and wealth, evolving from utopian to Marxist scientific socialism.
• Marx's scientific socialism 科学社会主义 provided a systematic critique of capitalism and a deterministic analysis of society and historical change.
• Anarchists 无政府主义者 asserted that all forms of governmental authority were unnecessary and should be replaced by a society based on voluntary cooperation.

Political movements and social organisations responded to the problems of industrialisation. The institutional side is equally examinable:

• Liberalism shifted from laissez-faire to interventionist 从自由放任转向干预 economic and social policies in response to industrialisation's challenges. This is the unit's most important intellectual change - the ideology that began by wanting the state out ended by using it.
• Reforms transformed unhealthy and overcrowded cities by modernising infrastructure, regulating public health, and reforming prisons.
• Reformers promoted compulsory public education 义务教育 to advance public order, nationalism, and economic growth. Note all three motives - the CED lists them, and none is purely benevolent.

The unit's reasoning skill is causation.

Worked example (a real AP exam question). AP European History short-answer questions here ask, for example, to "Explain one way in which industrialisation contributed to the development of new political ideologies in the nineteenth century." A full-mark answer traces the link: "Industrialisation created a large urban working class with common conditions and no political representation, which gave socialists a constituency and an argument: that the wealth produced by industry was distributed by ownership rather than by labour. Marx's scientific socialism turned that observation into a systematic critique of capitalism, and the concentration of workers in factories and cities made organising around it possible." Notice that the answer explains why the idea found an audience, not only that it existed.

• Britain's advantages include a political one - industrial interests were represented in Parliament. Most answers list only resources.
• France industrialised gradually with state support and less dislocation. That contrast answers many comparison questions.
• Learn the five ideologies as a set, distinguished by who holds power and what the state does.
• Liberalism's shift from laissez-faire to intervention is the century's key ideological change. Name it.
• Compulsory education had three motives - order, nationalism, growth. Give all three.
• Living standards rose by the end of the century, after decades of hardship. Timing is the mark.