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Manifest Destiny and the Commercial Conquest of the United States

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Grade Level(s):

6 - 12

Subject Area(s)

Language Arts - Reading and Writing, Civics, Geography, U.S. History

Estimated Time

One to two 45-50 minute class periods


When historian Tony Mares says that "the mercantile conquest of what would become the southwestern part of the United States was the real conquest," the implication is clear. The U.S. march to fulfill Manifest Destiny in western North America was not achieved by the military alone, but also by business people who explored what were then Mexican territories and served people and markets that were being ignored by the far-away Mexican government. In this activity, students will learn about the commercial conquest of this region via readings and video clips. Then the students will create their own "commercial conquest"! They will work in groups to write hypothetical commercials that could have been made by U.S. entrepreneurs of the time to reach out to their potential Mexican customers or by Mexican entrepreneurs encouraging the local population to “Buy Mexican.”.


Students will:

  • Learn about the importance of commerce in the U.S. effort to fulfill Manifest Destiny.
  • Explore the ways that U.S. businessmen filled a gap in the marketplace that had been created by Mexico's neglect of its territories.
  • Examine the ways that commerce and the military worked together to conquer western North America for the United States.
  • Think about the ways that American businessmen had to reach out to Mexican customers to gain their trust.
  • Apply some of their knowledge in a fun activity where they will write commercials that could have been made by the U.S. or Mexican entrepreneurs of the time.

Materials Needed

This activity can be completed using a computer lab where students can access the video clips and handouts themselves via "The U.S.-Mexican War" website. It can also be conducted by using a one classroom computer with a projection device. In the second scenario, you will need to provide the students with the following handouts:

Video clips used:


Pre-viewing Activity: Briefly review the previous activity by engaging students in a discussion about it. Then ask students to consider how they think Manifest Destiny actually became real for the United States. After all, we know that in the early 19th century, the U.S. did not extend west of the Mississippi; now, though, it reaches the Pacific Ocean and beyond. How do the students think this happened? Was it all a matter of military conquests? Ask students to brainstorm some potential answers.

Have the students read the article Manifest Destiny by Sam W. Haynes from the U.S.-Mexican War site. Ask the students to discuss some of the issues the article raises: the importance of technology in the U.S. spread to the Pacific: the concern about Britain and Mexico working together and keeping the U.S. from gaining lands it wanted; the belief of many in Manifest Destiny.

For additional background, you can reference the other excellent articles on Manifest Destiny on the U.S.-Mexican War site.

Briefly go over the questions on the Commercial Conquest worksheet with students before they watch the video clips:

  • Why were New Mexico and California considered so important by the U.S. government?
  • How did the central Mexican government treat its citizens in the outlying territories of New Mexico and California?
  • What was U.S. President James Polk's attitude toward acquiring New Mexico and California from the Mexican government?
  • How did the U.S. first gain influence in the territories of New Mexico and California?
  • What was the main trade route that the Americans used to reach New Mexico? What kinds of products did they sell to the people who lived in New Mexico?
  • Mexico had invited U.S. settlers to come to Texas and then ultimately lost control of that territory to those very same settlers. In the videos, there is discussion about how some of the Mexicans in New Mexico and California distrusted the new U.S. businessmen who were coming to their territories. They may have feared that history would repeat itself and the Americans would take their territories as well. What do you think may have been some strategies that the U.S.entrepreneurs used to reach out to their potential Mexican customers?

Viewing Activity: Tell students to go to “The U.S.-Mexican War” website to access the video clips “The United States declares war on Mexico,” “Kearney’s army marches west to conquer New Mexico and California,” “American entrepreneurs and the ‘mercantile conquest’ of the Southwest,” “American settlers head west to seek prosperity in California” (or display the videos with a projection device in your classroom). Explain to students that the clips will give them some insights into how commerce and military power combined to help the U.S. ultimately gain the lands of New Mexico and California from Mexico. Have students answer the questions on the Commercial Conquest worksheet after they have watched the videos.

Post-viewing Activity: Go over the content of the videos with the students, focusing particularly on the subjects addressed in the worksheet. Then read the previously mentioned quote from historian Tony Mares to the students:

"The mercantile conquest of what would become the southwestern part of the U.S. was the real conquest."

Ask students to discuss what they think that quote means and whether they believe it to be true.

Remind students that technological advances like the steamboat, railroad and the telegraph greatly helped with the U.S. move westward. One technology not invented yet was television. However, in the following activity, you are going to give the students the opportunity to do some time travel and bring TV back to the 19th century!

Break the class into groups of 4-5 students each. Tell the students that they are to assume the role of the mid-19th century U.S. entrepreneurs trying to ply their wares to the Mexican settlers in New Mexico... in a television commercial. Each group will work together to:

  1. Identify a product that real Mexican settlers would have been eager to buy.
  2. Develop a sales pitch that will reach out to potential Mexican customers who, for some very good reasons, may not have trusted the new American settlers/businessmen.
  3. Use the above to write a 30-second TV commercial for their product.
  4. Create a 30-second TV commercial urging Mexican customers to “Buy Mexican” instead of “Buy American”

The students should have fun with this activity; encourage them to be creative with it while displaying their knowledge about the topic. When the students have written their commercial scripts, have them read and/or perform them for their classmates. Have the students give each other feedback on their work.

Classroom Assessment

To assess the students' work, consider the following:

  • Did the students show an understanding of the commercial conquest of America in their answers on the worksheet?
  • Did the students show an understanding of these issues during the classroom discussion?
  • Did the students work well together in their groups?
  • Did the students' scripts show a grasp of the content?
  • Did the students' scripts exhibit a creative approach to the material?

Extensions and Applications

If you have access to video production equipment, follow up on this activity by having the students videotape the scripts for their commercials.

Students could also use the interactive timeline on the U.S.-Mexican War site to do map work on the Santa Fe Trail and/or to look at the great distances between Mexico City and some of Mexico's territories, particularly New Mexico and California. These great distances, and Mexico's relative neglect of its territories, gave U.S. entrepreneurs the opportunity to get a commercial foothold in these areas.

Another possibility is to have students use the timeline to do a population study of California and Texas in the second half of the 19th century. What percentage of the total U.S. population lived in these two states in 1850? 1860? 1870? What does the data say about the population shift in the U.S. during that time? What percentage of the U.S. population lived in these states according to the most recent census (2000)? What does the minority population of these states tell us about what America might look like in the coming years?

Students could also explore some of the excellent related articles on the PBS site, "The West":

For younger students: This activity could also be used by middle school students with little adaptation. They would certainly enjoy the challenge of coming up with ideas for a television commercial. You may need to simplify or omit some of the questions on the worksheet and/or answer the questions with the students as part of a classroom discussion.

National Standards

McRel K-12 Standards Addressed:

Language Arts

  • Standard 1: Uses the general skills and strategies of the writing process.
  • Standard 2: Uses the stylistic and rhetorical aspects of writing.
  • Standard 3: Uses grammatical and mechanical conventions in written compositions.
  • Standard 4: Gathers and uses information for research purposes.
  • Standard 5: Uses the general skills and strategies of the reading process.
  • Standard 8: Uses listening and speaking strategies for different purposes.


  • Standard 13: Understands the character of American political and social conflict and factors that tend to prevent or lower its intensity.
  • Standard 14: Understands issues concerning the disparities between ideals and reality in American political and social life.
  • Standard 23: Understands the impact of significant political and nonpolitical developments on the United States and other nations.


  • Standard 1: Understands the characteristics and uses of maps, globes and other geographic tools and technologies.
  • Standard 6: Understands that culture and experience influence people's perceptions of places and regions.
  • Standard 9: Understands the nature, distribution and migration of human populations on Earth's surface.
  • Standard 12: Understands the patterns of human settlement and their causes.
  • Standard 13: Understands the forces of cooperation and conflict that shape the divisions of Earth's surface.

U.S. History

  • Standard 9: Understands the United States territorial expansion between 1801 and 1861, and how it affected relations with external powers and Native Americans.
  • Standard 11: Understands the extension, restriction and reorganization of political democracy after 1800.

Online Resources

Below are the links for sites referenced in this activity:

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