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The War AtlasThe · War · Atlas

CLASSROOM ACTIVITY

Chase the citation

Pick one casualty figure, follow it to the source it rests on, and judge whether you trust it.

Grade band
High school / undergraduate
Duration
30–45 minutes
Materials
  • One computer per student or small group, with internet access
  • A battle page on The War Atlas and its linked source pages
  • This handout, printed (one per student or group)

Free to print & photocopy for classroom use · CC BY 4.0

A casualty figure in a history book looks like a fact. It is really the end of a trail: a historian read a source, which drew on a report, which counted — or estimated — the dead. This activity walks students down that trail. They pick one number on a battle page, follow it to the source the atlas cites, and decide for themselves how much to trust it.

We use Antietam — the bloodiest single day in American military history, and one of the most heavily documented battles in the catalogue — but any well-sourced battle works, and letting students pick their own is a good variant.

Steps

  1. Open the Antietam battle page. Find a casualty or force-strength figure and write it down, along with which side it belongs to.
  2. Scroll to the Sources section at the bottom of the page — these are the works the atlas draws on for this battle. Click into one source to open its own page.
  3. On the source page, record three things: what kind of source it is (a book or monograph, an article, a website), when it was published, and how many battles across the atlas cite it.
  4. Judge the source. Is it a primary source (written by someone who was there) or a secondarysource (a later historian’s synthesis)? Would you trust it for a casualty count? Why or why not?
  5. Write two sentences tracing your number from the battle page to the source you landed on, and say how confident you are in that number now compared with when you started.

Discussion questions

  • Where does a number in a history book actually come from? Is a figure more trustworthy because it’s printed, or because you can follow it to a source?
  • What is the difference between a primary and a secondary source for a casualty count? Which would you rather have — and why can we not always get it?
  • The atlas grades this battle’s casualty figures “medium” confidence. After looking at the sources, does that grade seem too cautious, about right, or too generous?
  • If you found the same number in three different books that all cite each other, is that three sources confirming it — or really just one?

Teacher notes

The feature this exercises: every battle page ends with a Sources section, and each source is its own page showing its type, publication year, and everything in the atlas that cites it. That link trail is the whole lesson — numbers have provenance, and the site lets you walk it.

Why Antietam: it is famous and unusually well documented, so students will find many sources to choose from. Any battle with a Sources section works; a good variant is to let each student pick a different battle and compare how deep the citation trail goes.

What “right” looks like: the aim is source evaluation, not a single verdict. A student who argues that a respected secondary synthesis is trustworthy is right; so is one who wants to chase it further back toward the original returns. Reward the reasoning, not the conclusion.

Grade-band note:written for high school and undergraduate. The primary-versus-secondary distinction in step 4 is the main lift; for younger students, replace it with the simpler question “was this written at the time, or written later?”