Lesson on Critical Thinking Skills for TAKS preparation software (Sleek, 2002)

Thinking Like an Historian

Old census records, membership lists, and words to a folk song—most people would have a hard time imagining anything more boring. But to an historian, these are clues to one of America's mysteries: the operations of the Underground Railroad. During the years before the Civil War, this secret network helped thousands of enslaved persons escape to freedom.

After 1850, federal law required that escaped slaves be returned to their masters. So those who dared to help fugitive slaves kept few written records. Historians must piece the story of the Underground Railroad together from the clues that survive. Their detective work is based on critical thinking skills like comparison/contrast and sequencing. These skills, which you've learned about in other classes, have special importance in history.

For example, historians know that every source has a bias, or a particular point of view. Sometimes the bias is deliberate, as when Paul Revere portrayed the British as "butchers" in his engraving of the Boston Massacre. Sometimes the bias is simply the result of a limited point of view; for example, some of the witnesses to the Boston Massacre heard the shots but did not see the confrontation between the mob and the British soldiers. To get a broad picture instead of a biased view, historians compare and contrast all available sources.

Sequencing is another skill of particular importance to historians. Hitler claimed that he invaded Poland after German troops were provoked by Polish officers. However, evidence presented at the Nuremburg trials showed that preparations for an invasion had begun months before.

To keep from being overwhelmed by facts and sources, historians use skills like categorizing, generalizing, inferring, finding the main idea, and summarizing. Instead of listing every country that Alexander the Great conquered, for example, they might summarize his conquests, "In the fourth century BCE, Alexander the Great spread Greek ideas through most of the known world."

The chart below provides an overview of the thinking skills most useful to historians—and to you, as you think about history. Why spend time trying to understand the past? As Winston Churchill said, "The farther backward you can look, the farther forward you are likely to see."

Thinking Skill




Organizing items or ideas into classes

"industrialized nations" versus "developing nations"


Finding similarities

The legal systems of the United States and Great Britain are both shaped by English common law.


Finding differences

The United States is a federal democracy; Great Britain is a constitutional monarchy.

Drawing inferences and conclusions

Making deductions from facts

Based on overseers' records, historians estimate that the Underground Railroad helped about 1,000 people a year escaped to freedom.

Finding the main idea

Identifying the most important information

Early cities usually grew up along trade routes or rivers.

Identifying cause-and-effect relationships

Connecting the reason something happened (cause) with the end result (effect)

Great Britain and France declared war against Germany because Hitler invaded Poland.

Making generalizations

Reasoning from many facts to broad principles

The rate of urbanization is increasing around the world.


Arranging in order of time or occurrence

When Andrew Jackson defeated the British at the Battle of New Orleans on Jan. 8, 1815, news of the peace treaty signed Dec. 24, 1814, had not reached him.


Briefly stating the most important information

The Olmecs are called the "mother civilization" of the Americas.