Evaluating Conflicting Evidence: Sultana

Essential Question

How do we use research sources to unravel a 150-year-old mystery?


In this lesson, students investigate a historical mystery—the 1865 explosion of the steamship Sultana—by analyzing a collection of primary and secondary source documents. They work in cooperative reading groups to complete a jigsaw activity in which they weigh the merits of two competing theories about the disaster, then come to a conclusion based on the available evidence.

Related HDSI Episode: The Sultana Investigation

It was April of 1865. The Civil War was newly ended, and steamboats were regularly traveling up the Mississippi River to take soldiers back to their homes. One such steamboat, the Sultana, left Vicksburg on April 24 to carry soldiers up to Cairo, Illinois. Tragically, just three days later, the boat caught fire and more than 2000 passengers had an impossible choice to make: burn to death on the boat or jump overboard and risk drowning. More than 1800 people died that day, but to this day, no one knows conclusively what caused the explosion. Was it an accident? Or was it an act of sabotage, one final blow struck by the Confederacy against the Union? Wes Cowan, Tukufu Zuberi, and Kaiama Glover set out to solve the mystery.

Suggested Grade Level

This lesson is written for grades 9-10, but can be adapted for use in grades 6-12. For middle school grades, primary source analysis can be simplified by highlighting the most important portions of the documents. For grades 11-12, lesson can be made more challenging by withholding the theories from the students, asking them to formulate their own theories of the Sultana explosion and then back up that theory with the supplied evidence. Be sure to have students explain why they valued some documents over others.

Suggested Unit of Study

This lesson would fit into American History units covering the Civil War and Reconstruction.


Estimated Time Required

2 class periods


The Civil War lasted four years, from 1861 through 1865. After the war, soldiers were released from Prisoner of War camps and slowly began to make their way back to their homes and families. Many prisoners traveled home by way of the Mississippi River, on large steamboats. The Sultana was one such steamboat. On April 24, 1865, it set a course through a country ravaged by years of war and a populace tense and fatigued from years of fighting. On its journey, it caught fire, resulting in the deaths of more than 1800 of its passengers. The federal government investigated the explosion, but never reached a conclusion as to its cause. Two competing theories have arisen among the historians and amateur historians who have studied the tragedy. Some claim it was a tragic accident, a boiler explosion due to a botched repair job. Others claim the boiler exploded thanks to the efforts of Confederate “boat burners,” who planted a bomb to deliberately sabotage the steamship.

Set Up

  • Make photocopies of the “Evaluating Conflicting Evidence” reproducible.
  • Make copies of the Reproducible “The Sinking of the Sultana: The Evidence.” You will hand out one source to each “Document Group” of students.   
  • Bookmark the following website (referenced on the “The Sinking of the Sultana: The Evidence” reproducible) on student computers or tablets, or print out and photocopy:


Tackling the mystery of the SS Sultana

The story of the SS Sultana. What caused the deadly explosion?

Show students the video “Introduction to the Sultana Mystery” from the History Detectives Special Investigations - Civil War Sabotage?  Use the following questions to lead a discussion after students view the video or read the background paragraph above.   

  • What was the Sultana? (Steamboat tasked with taking soldiers up the Mississippi, to their homes, after the end of the Civil War) What happened to it?  (There was an explosion and it caught fire, killing more than 1800 people)
  • What are the two theories about the explosion aboard the boat? (It was accident due to a faulty boiler repair and corruption; it was Confederate sabotage)
  • Why do you think this historical event has received so little attention in the history books? Make a speculation.


For the jigsaw activity, assign each student to two groups: first, a Document Group (A, B, C, or D), and second, a Home Group (each Home Group should have at least four students, one representative from each Document Group; label groups using numbers for clarity, i.e. 1, 2, 3, etc.). Pass out copies of the  “The Sinking of the Sultana: The Evidence” and “Evaluating Conflicting Evidence” reproducibles to each student.

Explain to the class that they will be examining primary sources and secondary sources related to the burning of the Sultana. Their task is to use these documents to evaluate the two competing theories of what happened to the Sultana and reach a conclusion as to which theory is more likely. The documents students will study are:

  • Group A: Excerpts from The Loss of the Sultana and Reminiscences of Survivors: Book of survivor stories and memories, collected by Chester D. Berry and published in 1892, 27 years after the disaster.
  • Group B: History Detectives interviews with the Experts: Modern day steamship experts speculate on the possible causes of the explosion aboard the Sultana
  • Group C: “The Courtenay Coal Torpedo,” an article about Thomas Edgeword Courtenay, inventor of the coal torpedo, and Confederate sabotage during the Civil War; includes embedded primary sources
  • Group D: Testimony from the Washburn Committee Report: Testimony of William Butler, a cook aboard the Sultana, from the Washburn Committee Report. The Washburn Committee was tasked with determining the cause of the Sultana tragedy by the United States federal government.

Students will begin their work in their Document Groups, investigating the source they have been assigned. In their Document Groups, students will

  • Take notes on their source(s) using the “Evaluating Conflicting Evidence” reproducible
  • Share their notes with one another
  • Discuss what theory their source best supports, coming to a consensus. Remind students their source may contain conflicting evidence and they do not need to be 100% sure which theory they believe at this point.

After students have investigated their sources in their Document Groups, they will assemble in their Home Groups. In their Home Groups, students will:

  • Share their notes about the source they investigated in their Document Groups in order to “teach” the other members of their group
  • Take notes on the “Evaluating Conflicting Evidence” reproducible
  • Discuss what theory they believe is the most probable based on all the evidence, coming to a consensus. Remind students they are looking for the most probable theory, not necessarily an irrefutable theory.
  • Discuss whether they changed their opinion on the best theory from their best guess in their Document Groups and why or why not.

During the group work, encourage the students to “Think Like a Historian.” Prompt students to use the 3 C’s and an S strategy when investigating the documents related to the Sultana tragedy.

  • Sourcing: Who made this source? Where did it come from?
  • Contextualizing: Imagine the setting surrounding this source: How was the world that made this source different than our own?
  • Corroborating: What do other sources say about the information in this document? Do they agree or disagree with what this document says?
  • Close Reading: What does the document say? Is it biased? What is the tone?

After students have examined and evaluated the evidence, lead a discussion about their conclusions based on the questions on the “Evaluating Conflicting Evidence” reproducible.

  • What document do you find the most persuasive? What document do you find the least persuasive? Why is the former more credible than the latter?
  • Based on the evidence presented, which theory regarding the sinking of the Sultana is more plausible?
  • What evidence best supports the theory your group thinks is correct? What in particular about these pieces of evidence does your group find convincing?
  • What evidence contradicts the theory your group thinks is correct? Why did your group choose to discount this evidence?
  • Based on your experiences in conducting this investigation, how do historians come to a consensus about a historical event when presented with conflicting evidence?

Wrap Up

Sultana mystery reveal

The History Detectives come to a conclusion about the Sultana mystery.

Show the video" "The Mystery of the Sultana: Reveal."

Give students an opportunity to answer the questions in Part 3 of the “Evaluating Conflicting Evidence” reproducible independently. Then lead a class discussion based on their answers.

  • What did you learn about the Civil War and its immediate aftermath from conducting this investigation?
  • Why is studying events such as the sinking of the Sultana an important historical endeavor?
  • What did you learn from the primary source documents that you did not or could not learn in a textbook?
  • How did this investigation change your understanding of the Civil War? Of Abraham Lincoln? Of war in general?

Going Further

The strategies and jigsaw strategy and the "Evaluating Conflicting Evidence" reproducible featured in this lesson plan can be used to develop another lesson where students investigate another historical mystery with competing theories. Some possibilities:

After pulling together a range of sources for students to examine, you may ask students to summarize the competing theories about the mystery, find evidence that supports the various theories, and then choose the most plausible theory based on the available evidence.

More on History Detectives

Use the following episodes or lesson plans from History Detectives to support the teaching of this lesson in your classroom. 

Episode: Civil War Letters

Lesson Plan: Using Primary Sources: Nazi Spy Ring Busted

Detective Technique Guide: Going Back in Time


Remember Sultana
National Geographic article about the sinking of the Sultana

Sultana: A Case for Sabotage
Comprehensive case for sabotage aboard the Sultana
, including various primary sources

Loss of the Sultana and Reminiscences of Survivors
Loss of the Sultana
, Full text of Chester D. Berry’s book, originally published 1892, on Google Books


This lesson aligns with these National History Standards, US History Content Standards and Common Core State Standards.