1619年

The first recorded arrival of enslaved Africans in the English colonies occurred in 1619 at Point Comfort, Virginia, marking the beginning of institutionalized slavery in what would become the United States. Approximately 20 Africans were brought by English privateers who had seized them from a Portuguese slave ship. These individuals were initially treated as indentured servants, but over time, the legal status of Africans in the colonies shifted to permanent, hereditary slavery. This event laid the foundation for the economic and social systems that would later fuel sectional tensions between the North and South. The development of slavery in the colonies was influenced by the demand for labor in tobacco cultivation and other cash crops. By the 18th century, slavery had become deeply entrenched in Southern society, creating a stark contrast with Northern states where slavery was gradually abolished after the American Revolution.

1787年

The Constitutional Convention of 1787 addressed the issue of slavery through several compromises, most notably the Three-Fifths Compromise, which counted enslaved individuals as three-fifths of a person for representation and taxation purposes. This agreement reflected the growing divide between Northern and Southern states over slavery. The Constitution also included a clause prohibiting Congress from banning the importation of enslaved people until 1808, demonstrating slavery's entrenchment in the new nation's legal framework. James Madison's notes from the convention reveal heated debates about slavery's future, with some Northern delegates opposing the institution while Southern delegates threatened to leave the union if slavery was threatened. These compromises temporarily preserved national unity but established legal protections for slavery that would later contribute to sectional conflict.

1820年

The Missouri Compromise of 1820 attempted to maintain the balance between free and slave states by admitting Missouri as a slave state and Maine as a free state, while prohibiting slavery in the Louisiana Territory north of the 36°30′ parallel (except within Missouri). Proposed by Henry Clay, this legislation temporarily eased sectional tensions but established the precedent of congressional involvement in slavery's expansion. The debate revealed deep divisions, with Northern congressmen like James Tallmadge Jr. proposing amendments to gradually abolish slavery in Missouri. Southerners, led by South Carolina's William Smith, argued that Congress had no right to restrict slavery in new territories. Thomas Jefferson famously described the crisis as 'a fire bell in the night,' warning that the slavery question threatened the Union's survival. The compromise merely postponed rather than resolved the fundamental conflict over slavery's expansion.

1850年

The Compromise of 1850, another series of legislative measures brokered by Henry Clay, attempted to resolve disputes over territory acquired from Mexico in the Mexican-American War. It included California's admission as a free state, a stronger Fugitive Slave Act, the abolition of the slave trade (but not slavery itself) in Washington D.C., and popular sovereignty for New Mexico and Utah territories. The Fugitive Slave Act proved particularly controversial, requiring citizens to assist in capturing escaped slaves and denying alleged fugitives jury trials. This law radicalized many Northerners, including previously moderate abolitionists. Daniel Webster's famous 'Seventh of March' speech supporting the compromise alienated his anti-slavery constituents. The compromise temporarily preserved the Union but intensified sectional animosities, with Northern states passing personal liberty laws to nullify the Fugitive Slave Act, while Southerners grew increasingly defensive about their 'peculiar institution.'

1854年

The Kansas-Nebraska Act of 1854, introduced by Illinois Senator Stephen A. Douglas, repealed the Missouri Compromise by allowing settlers in the Kansas and Nebraska territories to decide through popular sovereignty whether to permit slavery. This legislation led to violent conflicts known as 'Bleeding Kansas,' as pro-slavery 'Border Ruffians' from Missouri clashed with anti-slavery 'Free-Staters.' The act destroyed the Whig Party, gave rise to the Republican Party (founded explicitly to oppose slavery's expansion), and further polarized the nation. Abraham Lincoln re-entered politics in opposition to the act, delivering his famous 'Peoria Speech' condemning slavery's potential spread. The violence in Kansas, including John Brown's 1856 Pottawatomie massacre where five pro-slavery settlers were executed, demonstrated how the slavery debate had moved beyond political compromise to physical confrontation. The Supreme Court's 1857 Dred Scott decision would later declare all congressional restrictions on slavery unconstitutional.

1860年11月

Abraham Lincoln's election as president on November 6, 1860, triggered the secession crisis. Although Lincoln received only 39.8% of the popular vote and no Southern electoral votes, his victory on an anti-slavery-expansion platform alarmed Southern states. South Carolina's legislature called a secession convention within weeks, unanimously adopting an Ordinance of Secession on December 20. The state's 'Declaration of Immediate Causes' cited Northern states' resistance to the Fugitive Slave Act and the election of 'an avowed enemy of slavery' as justification. President James Buchanan condemned secession as illegal but claimed the federal government lacked authority to stop it. Meanwhile, Congress attempted last-minute compromises, including the Crittenden Compromise proposing constitutional amendments to protect slavery, which Lincoln opposed. By February 1861, six more Deep South states had seceded, forming the Confederate States of America with Jefferson Davis as president. The Upper South remained in the Union temporarily, awaiting developments.

1861年4月12日

The American Civil War began on April 12, 1861, when Confederate forces under General P.G.T. Beauregard bombarded Fort Sumter in Charleston Harbor, South Carolina, after Union Major Robert Anderson refused to surrender the federal installation. Following 34 hours of bombardment that caused no fatalities (though one Union soldier later died in an accidental explosion during the surrender ceremony), Anderson surrendered the fort. Lincoln's subsequent call for 75,000 volunteers to suppress the rebellion prompted Virginia, Arkansas, Tennessee, and North Carolina to join the Confederacy, bringing the total to 11 states. The attack united Northern public opinion behind preserving the Union, while Southerners saw it as a justified defense against Northern aggression. The war would ultimately claim approximately 620,000 lives (recent scholarship suggests possibly 750,000), making it America's deadliest conflict. The bombardment's immediate aftermath saw both sides rapidly mobilize, with Confederate troops seizing numerous federal installations across the South and Lincoln imposing a naval blockade.

1863年1月1日

President Lincoln issued the Emancipation Proclamation on January 1, 1863, declaring all enslaved people in Confederate-held territory 'forever free.' This executive order did not immediately free anyone (as it exempted border states and Confederate areas under Union control), but it fundamentally transformed the war's purpose from solely preserving the Union to also ending slavery. The proclamation authorized the enlistment of Black soldiers, with nearly 200,000 eventually serving in the U.S. Colored Troops. Internationally, it prevented British and French recognition of the Confederacy by framing the war as an anti-slavery crusade. Lincoln had delayed the proclamation until after the Union victory at Antietam to avoid appearing desperate. While abolitionists like Frederick Douglass praised it, some Northern Democrats condemned it as unconstitutional. The proclamation's limitations—it didn't abolish slavery nationwide—were addressed by the 13th Amendment in 1865. Modern historians view it as one of history's most significant uses of executive power.

1863年7月1日 ~ 1863年7月3日

The Battle of Gettysburg (July 1-3, 1863) marked the Civil War's turning point. General Robert E. Lee's second invasion of the North culminated in this Pennsylvania engagement against General George G. Meade's Army of the Potomac. The three-day battle involved approximately 165,000 troops and resulted in 51,000 casualties. Key moments included the Union defense of Little Round Top by Colonel Joshua Chamberlain's 20th Maine, Pickett's disastrous charge on July 3 (where nearly 50% of 12,500 Confederates became casualties), and Lee's retreat on July 4. Coupled with Vicksburg's surrender that same day, Gettysburg ended Confederate offensive capabilities. Lincoln's brief Gettysburg Address later reframed the war as a struggle for equality. The battle's aftermath saw improved Union morale and European powers abandoning Confederate recognition hopes. Modern archaeology continues to uncover artifacts, while debates persist about Lee's decisions and Meade's failure to pursue.