6.3 Westward Expansion, Sectional Conflict, the Civil War, and Reconstruction

6.3 Westward Expansion, Sectional Conflict, the Civil War, and Reconstruction

CSET Focus: CSET Multiple Subjects Subtest I extensively examines the turbulent 19th-century transformation of the United States. Candidates must be prepared to analyze the ideological and geopolitical forces behind westward migration, the catastrophic displacement of Indigenous nations, the structural economic divergence between North and South, the sequence of failed legislative compromises over slavery, key Civil War strategic turning points, and the constitutional and social legacy of Reconstruction and Jim Crow.

1. Westward Expansion, Manifest Destiny, and Indigenous Removal

Throughout the 19th century, the United States pursued rapid geographic expansion from the Atlantic to the Pacific Ocean, driven by the popular ideology of Manifest Destiny (a term coined in 1845 by editor John L. O'Sullivan), which asserted that the nation held a divinely ordained mission to spread democratic institutions across the continent.

[Louisiana Purchase 1803] ──> [War of 1812] ──> [Indian Removal Act 1830] ──> [Texas & Oregon 1845-46] ──> [Mexican Cession 1848]

Major Territorial Acquisitions

• The Louisiana Purchase (1803): President Thomas Jefferson purchased 828,000 square miles of territory from Napoleonic France for $15 million, instantly doubling the geographic size of the United States and securing control of the vital Mississippi River port of New Orleans. Jefferson dispatched the Lewis and Clark Expedition (Corps of Discovery, 1804–1806), aided by Shoshone guide Sacagawea, to map the Pacific route and document resources.
• The War of 1812: Fought against Great Britain over British impressment of American merchant sailors, trade blockades, and British military support for Indigenous resistance in the Northwest Territory (led by Shawnee chief Tecumseh). Ended with the Treaty of Ghent (1814) and Andrew Jackson's victory at New Orleans (1815), stimulating domestic manufacturing and fostering intense nationalistic pride ("Era of Good Feelings").
• Texas Annexation (1845): American settlers in Mexican Texas revolted in 1836 (Battle of the Alamo, Battle of San Jacinto), creating the independent Republic of Texas. The US annexed Texas in 1845, inflaming border tensions with Mexico.
• Oregon Treaty (1846): President James K. Polk negotiated a peaceful boundary settlement with Great Britain, establishing the 49th parallel as the northern border to the Pacific.
• The Mexican-American War (1846–1848) & Mexican Cession: Sparked by a border skirmish along the Rio Grande. The war concluded with the Treaty of Guadalupe Hidalgo (1848), wherein Mexico ceded over 500,000 square miles—the Mexican Cession (including present-day California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado and Wyoming) in exchange for $15 million. The discovery of gold at Sutter's Mill in 1848 triggered the 1849 California Gold Rush, precipitating California's rapid application for free-state status in 1850.

Indigenous Dispossession and the Trail of Tears

As white settlement pushed westward, the federal government systematically dispossessed Indigenous nations:

• Indian Removal Act of 1830: Signed by President Andrew Jackson, authorizing the forced relocation of southeastern native nations to territory west of the Mississippi River (modern-day Oklahoma).
• Worcester v. Georgia (1832): The Supreme Court, led by Chief Justice John Marshall, ruled that the Cherokee Nation was a distinct political community in which the laws of Georgia had no force, affirming federal treaty obligations. President Jackson notoriously defied the ruling, refusing to enforce it.
• The Trail of Tears (1838–1839): Under President Martin Van Buren, the U.S. Army forced over 16,000 Cherokee from their ancestral homelands at gunpoint. Over 4,000 Cherokee died from exposure, starvation, and dysentery during the brutal 1,200-mile winter march, alongside thousands of Choctaw, Creek, Chickasaw, and Seminole victims of forced removal.

2. Sectionalism and the Escalation of the Slavery Crisis

By 1850, the United States was deeply polarized along regional, economic, and ideological lines:

• The North: Developing an industrial, urbanized economy powered by free wage labor, manufacturing, financial centers, extensive railroad infrastructure, and support for high protective tariffs.
• The South: An agrarian, monoculture export economy dominated by "King Cotton" (entrenched following Eli Whitney's 1793 invention of the cotton gin), dependent upon hereditary racial chattel slavery, opposed to tariffs, and fiercely committed to states' rights doctrine.

[Missouri Compromise 1820] ──> [Compromise of 1850] ──> [Kansas-Nebraska Act 1854] ──> [Dred Scott 1857] ──> [Lincoln Elected 1860]

Sequence of Sectional Compromises and Catalysts for War

3. The American Civil War (1861–1865): Strategy, Battles, and Emancipation

Armed hostilities commenced on April 12, 1861, when Confederate batteries bombarded the federal garrison at Fort Sumter in Charleston Harbor, South Carolina.

Comparative Strengths and Strategic Doctrines

• Union (North) Advantages: Overwhelming population (22 million vs. 9 million in South, including 3.5 million enslaved); 85% of national manufacturing and factories; 70% of total railroad mileage; established banking systems; superior naval supremacy.
  • Union Strategy: General Winfield Scott's Anaconda Plan—blockade Southern Atlantic and Gulf ports, seize control of the Mississippi River to bifurcate the Confederacy, and capture the Confederate capital at Richmond, Virginia.
• Confederacy (South) Advantages: Fighting a defensive war on familiar interior terrain; highly motivated soldier corps defending their homeland; outstanding early military commanders (Robert E. Lee, Thomas "Stonewall" Jackson); initial hope for European diplomatic intervention via "Cotton Diplomacy."

Decisive Military Milestones

1. Battle of Antietam (Sharpsburg) (September 17, 1862): Bloodiest single-day battle in American history (over 23,000 casualties). Union General George McClellan halted General Lee's first invasion of Maryland. This tactical victory provided President Lincoln the vital political momentum to issue the preliminary Emancipation Proclamation.
2. The Emancipation Proclamation (January 1, 1863): Lincoln issued this executive order under his constitutional authority as Commander in Chief. It declared that all enslaved persons in areas in rebellion against the United States were forever free:
   • Strategic Impact: Transformed the war from a struggle solely to preserve the Union into a moral crusade to abolish slavery; permanently deterred Britain and France from recognizing the Confederacy; authorized the enlistment of African American soldiers into the Union Army and Navy (over 180,000 Black soldiers served, including the celebrated 54th Massachusetts Infantry).
3. Battle of Gettysburg (July 1–3, 1863): General Lee's second invasion of the North ended in catastrophic Confederate defeat in Pennsylvania, culminating in the disastrous repulse of Pickett's Charge. Gettysburg represented the military high-water mark of the Confederacy, after which Lee remained permanently on the defensive. In November 1863, Lincoln delivered the Gettysburg Address, dedicating the cemetery and redefining the war as a struggle for "a new birth of freedom."
4. Siege of Vicksburg (concluded July 4, 1863): Union General Ulysses S. Grant captured the Confederate fortress city of Vicksburg, Mississippi, granting the Union total control of the Mississippi River and slicing the Confederacy in two.
5. Sherman's March to the Sea (1864): Union General William Tecumseh Sherman captured Atlanta and marched across Georgia to Savannah, practicing total war by destroying Confederate rail lines, factories, cotton crops, and infrastructure, breaking the South's economic and psychological will to fight.
6. Appomattox Court House (April 9, 1865): Encircled and exhausted, General Robert E. Lee surrendered the Army of Northern Virginia to General Ulysses S. Grant, effectively concluding the Civil War. Five days later, on April 14, 1865, President Lincoln was assassinated by John Wilkes Booth at Ford's Theatre.

4. Reconstruction (1865–1877): The Struggle for Civil Rights

Following the Civil War, the nation faced the daunting challenge of reintegrating eleven former Confederate states, rebuilding the devastated Southern economy, and securing the civil rights of four million emancipated African Americans.

Competing Reconstruction Visions

• Presidential Reconstruction: Lincoln proposed the lenient 10% Plan (a state could re-establish government once 10% of voters took an oath of allegiance). Following Lincoln's death, President Andrew Johnson implemented an ultra-lenient policy, granting pardons to ex-Confederate leaders and allowing Southern states to enact Black Codes (draconian laws designed to restrict Black freedom, labor mobility, and force freedpeople into exploitative agricultural labor).
• Radical (Congressional) Reconstruction: Angered by Johnson's leniency and Southern intransigence, Radical Republicans led by Thaddeus Stevens and Charles Sumner seized control of Congress, overriding Johnson's vetoes and passing the Military Reconstruction Acts of 1867, which divided the South into five occupied military districts governed by federal generals and required states to ratify new constitutions guaranteeing Black suffrage.
• The Freedmen's Bureau (1865): Established by Congress to provide emergency food, medical aid, legal labor contract assistance, and establish public schools and historically Black colleges (e.g., Howard, Fisk, Morehouse) for formerly enslaved people and poor whites.

The Reconstruction (Civil War) Amendments

The Collapse of Reconstruction and the Rise of Jim Crow

1. Southern Resistance & White Supremacy: The rise of paramilitary terrorist organizations, notably the Ku Klux Klan (KKK) founded in 1866, which used lynching, voter intimidation, and arson to suppress Black political participation and restore white supremacy.
2. Economic Subjugation via Sharecropping: Lacking capital and land, millions of freedpeople entered sharecropping agreements, farming a white landlord's land in exchange for a share of the harvest. Landlords charged exorbitant prices for seed and tools via crop liens, trapping generations in inescapable cycles of debt peonage.
3. The Compromise of 1877: The disputed presidential election of 1876 between Rutherford B. Hayes (Republican) and Samuel J. Tilden (Democrat) was settled by an informal political bargain: Hayes was awarded the presidency in exchange for the complete withdrawal of remaining federal occupation troops from the South. This ended Reconstruction and returned political power to Southern "Redeemer" Democrats.
4. Jim Crow Segregation & Disenfranchisement: Following 1877, Southern states enacted comprehensive de jure segregation laws (Jim Crow) and systematic voter suppression tactics (poll taxes, literacy tests, grandfather clauses). In Plessy v. Ferguson (1896), the Supreme Court upheld state-mandated racial segregation under the doctrine of "separate but equal," entrenching institutionalized segregation for nearly six decades.