Chapter 14
Western Expansion and the Rise of the Slavery Issue
1820–1850
LEARNING OBJECTIVES
• Explain the concept of Manifest Destiny, the experience of the Mexican borderlands, and
the events that led to the emergence of the Texas Republic.
• Describe the Overland Trail and the experiences of those on and around it.
CHAPTER OVERVIEW
Americans traditionally linked western migration with the preservation of opportunity. The
revolutions in markets and transportation greatly accelerated the process of white settlement
beyond the Appalachian Mountains. Similarly, the spread of cotton production and the quest for
economic success had carried southerners, white and Black, free and slave, westward. Thus,
white southerners linked western expansion with not only the preservation of white opportunity
but also the preservation of slavery. As the lines of settlement spread across the Mississippi
This chapter examines the Republic’s expansion to the Pacific Ocean, its transformation into a
continental nation, and how that development injected the slavery issue into national politics. It
begins with the expansion of the Sioux onto the Plains, as a reminder that westward expansion in
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THEMES
Manifest (and Not So Manifest) Destiny
In the 1840s, Americans proclaimed that it was the United States’s “Manifest Destiny” to expand
across the North American continent. This doctrine combined idealistic motives with attitudes of
racial superiority and a hunger for good farmland. This destiny brought Americans into contact,
The Trek West
Lured by the promise of good land and a fresh start, and following an earlier generation of
mountain men and fur traders whose business declined toward the middle of the century, other
Americans headed for Oregon and California on the Overland Trail. Most migrants traveled in
The Political Origins of Expansion
The desire of the people of Texas to be annexed to the United States initially was blocked by
politicians’ fears of raising the slavery issue, since Texas had legalized slavery. The death of the
Whigs’ first president, William Henry Harrison, only a month after he assumed office, however,
brought John Tyler to the presidency. A proponent of states’ rights, Tyler soon broke with the
Whigs over economic policy. As a result, he took up the Texas issue in the hope of winning
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New Societies in the West
Overlanders sought to recreate in the West the society they had left behind. With time, these
societies became more stable and their economies more diversified. At the same time, wealth
became more concentrated and opportunity more constricted. The discovery of gold in California
set off a frantic rush to the diggings and triggered a brutal genocide of California natives. The
Escape from Crisis
Solution of the territorial question became urgent when gold was discovered in California in
1848. As miners flocked to the region, California quickly gained sufficient population to be
admitted as a state. In addition, Mormons in the Salt Lake basin asked for admission as a state.
When both major parties tried to avoid the issue of slavery’s expansion in 1848, northern
antislavery forces founded a new party, the Free Soil party, which urged adoption of the Wilmot
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LECTURE STRATEGIES
Western Expansion from the Native American Perspective
This chapter examines westward expansion in the 1840s and its connection to the rise of the
slavery issue in national politics. Western expansion in American history is usually thought of
Manifest Destiny
The doctrine of Manifest Destiny is worth exploring in more detail. Of particular interest in this
regard is Thomas Hietala’s Manifest Design: American Exceptionalism and Empire, which
Western Expansion and Settlement versus Expansion and National Politics
Thematically, this chapter divides into two major categories: the process of western expansion
and settlement and the interaction of expansion and national politics. You might wish to lecture
on these topics separately rather than follow the organization of the chapter, which moves back
Proposed Solutions to the Territorial Crisis
In the wake of the Mexican War, and the treaty of peace giving the United States the territory
Polk sought, it is important to outline the possible solutions to the territorial crisis. The options
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split both parties along sectional lines, but in different ways. Whigs were divided between
northern opponents of slavery’s expansion and southern moderates like Clay, who wanted to
keep slavery out of national politics, while Democrats were divided between northern moderates
TEACHING SUGGESTIONS
The Timing of Expansion and “Manifest Destiny”
“Timing”—why a series of events occurs when it does—is a problem historians routinely
address. Why did slavery entrench itself in Virginia in the 1670s and 1680s rather than during
the tobacco boom of the 1620s? Why did the thirteen colonies assert their independence in the
The Overland Trail
Students are often fascinated by the Overland Trail. A discussion on this topic might begin by
asking why they think it is so interesting, and what misperceptions they held about this subject
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Comparing New Western Societies
Students may also want to discuss the new societies formed in the West, comparing and
contrasting societies in various areas of the West, like Salt Lake City and San Francisco. Those
The Compromise of 1850
In the end, the system produced the Compromise of 1850. Students should understand its specific
provisions and the process by which it passed Congress. It is especially important to emphasize
that a majority in Congress was unwilling to accept all the provisions of the Compromise as a
POWER OF PROCESS FOR PRIMARY SOURCES
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primary sources. As part of Connect History, McGraw-Hill Education’s learning platform, Power
of Process contains a database of over 400 searchable primary sources in addition to the
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