Grade by Grade
D. The World, 1789–1900 · The World, 1789–1900

Be a Historian: What Was the Most Significant Change of 1789–1900?

A1.1 A1.2 A1.3 A1.4 A1.7 A1.8 A1.9 A2 D1 D2 D3About 75 minutes
Learning goals
  • I can plan and carry out a complete historical inquiry on the period 1789–1900.
  • I can use criteria to judge historical significance and defend my judgement.
  • I can evaluate online and print sources for credibility.
  • I can write a thesis, organize evidence, address a counter-argument and cite sources.
  • I can explain how inquiry skills are used in university and in careers.

Words to know

thesis
A clear, arguable claim that answers the inquiry question and that the rest of the essay supports.
criteria
Standards used to make a judgement, such as depth, breadth and durability of change.
counter-argument
A reasonable opposing view, which a strong essay acknowledges and answers.
annotated bibliography
A list of sources with a short note on each source's content, reliability and usefulness.
lateral reading
Checking a source's reliability by leaving it and seeing what other reliable sources say about it and its author.
historical significance
How much an event, person or development mattered: how deeply and widely it changed lives, for how long, and what it reveals.

Your turn to be the historian

In this lesson you will carry out a full inquiry on the whole unit. The question is deliberately big and debatable:

Which development of 1789–1900 was the most significant for the world: political revolution, industrialization, imperialism, abolition, or new ideas such as nationalism and women's rights?

There is no single correct answer. There are strong and weak arguments. University history courses mark you on exactly this: a clear thesis, good evidence, use of criteria, attention to different perspectives, and proper citations.

1. Formulatea question2. Gather andorganize evidence3. Interpretand analyse4. Evaluate andconclude5. Communicateand citeThe inquiry process (strand A)New evidence or a better question sends you back around the cycle.Use the historical thinking concepts at every step:significance • cause and consequence • continuity and change • perspective
The same cycle you have used all unit. Real inquiries loop back when new evidence appears.

Step 1: Sharpen the question

A big question needs a manageable focus. You might narrow it by region ("for Africa"), group ("for workers", "for women"), or time ("by 1900"). Example: Was industrialization or imperialism more significant for the lives of people in South Asia by 1900?

Step 2: Use criteria for significance

Historians often judge significance with criteria like these (based on the historical thinking concepts used in Canadian schools):

  • Depth: how deeply did it change people's lives?
  • Breadth: how many people, and in how many regions?
  • Durability: how long did the effects last? Are they still felt today?
  • Revealing: does it help us understand a larger issue (for example, how freedom was won, or how inequality was built)?

Also ask: significant to whom? The Haitian Revolution looked different from Port-au-Prince than from Paris.

Sample significance scores (one student's judgement, 1 to 5)DepthBreadthDurabilityRevealingIndustrialization5554Haitian Revolution5345Unification of Italy3243Scores are a thinking tool, not facts; you must defend each one with evidence.
One student's scores. Another student could defend different scores; what matters is the evidence behind each one.

Step 3: Gather and evaluate sources

Use a mix of primary sources (documents, images, statistics from the time) and secondary sources (historians' books and articles). For every source, especially online, ask:

  • Who made it, and what is their expertise or perspective?
  • When and why was it made?
  • What evidence does it give? Does it cite its sources?
  • Do other reliable sources agree? Use lateral reading: open a new tab and search for the author or organization to see what others say about them.

Good starting places: university press books, museum and archive websites, government heritage sites (such as Parks Canada or Library and Archives Canada), and encyclopedias written by named experts (such as The Canadian Encyclopedia). Be careful with anonymous websites, social media posts and AI-generated summaries: check every fact against a reliable source, and never cite a source you have not read.

Step 4: Analyse and argue

Organize evidence in a table by criterion. Write a thesis that answers the question and names your main reasons. Then find the strongest counter-argument and answer it.

Step 5: Communicate and cite

Choose a form that suits your audience: an essay, a podcast script, a museum panel or a short video. Cite every source with Chicago-style notes (see the lesson on industrial society) and include a bibliography.

Worked example

Modelled example: From evidence to thesis

Question: Was industrialization the most significant development of 1789–1900? Build a thesis with a counter-argument.

  1. Evidence by criterion: Depth: changed work, family life, cities and diets. Breadth: reached far beyond Britain through trade (Indian weavers, US cotton slavery, Egyptian cotton). Durability: the industrial economy still shapes the world, including climate change. Revealing: shows how global inequality (the Great Divergence) was built.
  2. Counter-argument: imperialism changed the lives of more people more directly by 1900: hundreds of millions lived under colonial rule in Africa and Asia.
  3. Rebuttal: imperialism on this scale depended on industrial power: steamships, railways, quinine production and machine guns. So industrialization was the deeper cause.
  4. Acknowledge limits: for enslaved people in the Americas, abolition may have been the most significant change in their lives. Significance depends on perspective.
  5. Thesis: combine claim, reasons and nuance.

Thesis: Industrialization was the most significant development of 1789–1900 because it transformed work and daily life on several continents, made possible the age of empire, and created a global inequality that lasts today; however, for millions of enslaved and colonized people, abolition and imperial conquest were the changes that most directly shaped their lives.

Just for fun

The footnote is so central to history that the historian Anthony Grafton wrote an entire book about it: The Footnote: A Curious History (1997). Yes, it has footnotes about footnotes.

Careers and university (A2)

The skills in this lesson are used far beyond history class:

  • Law: building an argument from evidence and answering the other side.
  • Journalism and communications: checking sources and writing clearly for an audience.
  • Public policy and government: comparing cases and judging which factors matter most.
  • Museums, archives and heritage: organizing primary sources and presenting them to the public; working with Indigenous communities on how their histories are shared.
  • Data analysis and business research: evaluating evidence and spotting bias.

In first-year university, history, political science, economics, Indigenous studies, law and many other programmes expect you to write a thesis-driven essay with citations, exactly as practised here.

Hands-on activity

Run your mini-inquiry

You need: a device with internet access (with a grown-up's permission) or a library, paper, and about 60 minutes (you can split it over two days).

  1. Question: choose and narrow the unit question (Step 1).
  2. Sources: find four sources: at least one primary and two secondary. For each, write two lines for an annotated bibliography (what it says; how reliable it is and why).
  3. Criteria table: fill in depth, breadth, durability and revealing for two developments.
  4. Thesis: write a one-sentence thesis and a one-sentence counter-argument with your reply.
  5. Communicate: write a 300-word paragraph or record a two-minute talk for your family, with citations.

Look for: a focused question, varied and credible sources, criteria used with evidence, a clear thesis, a fair counter-argument, and correct citations.

Your turn

1

Narrow this question: "Was imperialism significant?"

2

Name the four significance criteria used in this lesson.

3

What is lateral reading?

4

Why should a thesis include a counter-argument or limit?

5

Give two features of a credible secondary source.

6

Why is "significant to whom?" an important question?

7

Name two careers that use historical inquiry skills and explain one.

More practice: warm-up

1

What is a thesis?

2

Is a factory inspector's report from 1840 primary or secondary?

3

What does an annotated bibliography add to a normal bibliography?

4

Which citation style is usually used in university history?

5

Name one reliable Canadian online source for history.

More practice: on your own

1

Write a thesis arguing that abolition was the most significant development of 1789–1900.

2

You find a website with no author that says the Berlin Conference "divided Africa with a ruler in one afternoon". How do you evaluate it?

3

Use the "revealing" criterion to argue for the Haitian Revolution's significance.

4

Why is an AI-generated summary not a citable source on its own?

5

Choose an audience and format for presenting your inquiry, and explain your choice.

Challenge

1

Write a counter-argument and rebuttal to this thesis: "Nationalism was the most significant development of 1789–1900."

2

Explain how the choice of criteria can change the answer to a significance question.

3

Design a research plan (question, four sources, method) for: "How significant were the Numbered Treaties for First Nations on the Prairies?"

Check your understanding

Quiz

1.

Which criterion asks how long an event's effects lasted?

2.

What is the best first step for a big inquiry question?

3.

Lateral reading means:

4.

Which thesis is strongest?

5.

Why include a counter-argument in a history essay?

6.

Which is a credible secondary source for this unit?

For parents and teachers

Big idea: This lesson brings together all of strand A (A1.1 to A1.4, A1.7 to A1.9 and A2) using the content of strand D (D1, D2, D3). It is a capstone inquiry for the unit.

How to help: Be the audience for your teen's final paragraph or talk. Ask: What is your thesis? What is your best evidence? What would someone who disagrees say? Check that every source is real and cited.

Common difficulties: Choosing a question that is too big; listing facts instead of arguing; ignoring the counter-argument; using unreliable websites or AI summaries without checking; forgetting citations. Remind your teen that a well-supported answer different from yours is still a good answer.