1619 - 1800 

1619 - Slavery introduced at
Jamestown, Virginia
1783 -
Treaty of Peace
1787 -
Northwest Ordinance ban slavery in new territories of the Northwest.
1789 - United States Constitution is ratified. Acknowledges the existence of slavery indirectly and appears not to give Congress the power to abolish slavery, but sets 1808 as the date when Congress may abolish the slave trade.
1791 -
Amendment X ratified which guaranteed states rights.
1801 - 1830 

1806 -
Articles of War (the rules by which war is waged) was passed by Congress.
1808 -
Congress abolishes the slave trade.
1814 - The
Treaty of Ghent
1820 -
Missouri Compromise issued. Admits Missouri as a slave state and Maine as a free state; slavery is to be banned in future states above the 36° 30’ line. In the constitution written by the Missouri territory, free blacks and free mulattos are barred from the future state.
1821 - Mexican Independence from Spain. Mexico begins to invite Americans to settle Texas territory under the conditions that the settlers convert to Catholicism and observe Mexican laws, including the abolition of slavery.
1830 - Mexico passes an
Anti-Colonization Law to prevent Americans from further colonizing Texas.
1831 - 1835 

1831 - Abolitionist William Lloyd Garrison begins publishing The
1831 -
Nat Turner leads an uprising of approximately 70 slaves in Southampton, Virginia. 100 Virginia slaves are slaughtered in search of Turner; Turner is executed when found. The uprising so shakes Southern states that they pass more stringent laws related to slaves, increase censorship against abolition, and make military preparations to halt further uprisings.
1832 -
South Carolina’s Ordinance of Nullification. South Carolina legislature also adopts measures to enforce this ordinance, even allowing for military preparations and secession if the Federal government resorts to force.
1832 -
President Jackson’s Proclamation on Nullification.
1833 - Britain abolishes slavery in her colonies. America is becoming increasingly isolated as a nation that allows slavery
1835 - Santa Anna, President of Mexico, proclaims a unified constitution for all Mexican territories, including Texas. North
American settlers in Texas announce that they intend to secede from Mexico rather than give up their "right" to slavery, which Mexico had abolished.
1836 - 1840 

1836 - The Battle of the Alamo. President Santa Anna leads a siege on the Alamo, in an attempt to defend his idea of a unitary state. Mexican soldiers overwhelm the fort, but the Texans’ heroic defense of the Alamo inspires North American settlers to secede.
1836 - Texans declare independence from Mexico. They name Sam Houston commander of their army, and adopt a constitution that formally legalizes slavery in Texas.
1836 - Texans defeat Mexicans and capture Santa Anna at the battle of San Jacinto. The Texans ratify their own constitution, elect Sam Houston as President, and send an envoy to Washington to demand annexation or recognition of the independent Republic of Texas. Annexation of Texas will remain a controversial issue for the next nine years, as it pits pro-slavery Southerners against anti-slavery Northerners.
1840 - Whig William Henry Harrison is elected President, and John Tyler is his Vice President.
1841 - 1845 

1841 - William Henry Harrison dies of pneumonia after only one month in office. Vice President John Tyler becomes the first American to succeed to the presidency.
1841 -
Frederick Douglass delivers his first recorded anti-slavery speech
1842 - The
Webster-Ashburton Treaty between the United States and Great Britain is signed, whose purpose was to settle and define the boundaries between the United States and Great Britain in North America, for the final suppression of the African slave trade, and for the giving up of criminals fugitive from justice
1843 - Santa Anna, President of Mexico, warns that he would consider the American annexation of Texas as tantamount to a declaration of war against Mexico.
1844 - James Polk, Democrat, defeats Whig Henry Clay for the presidency. Polk is somewhat unknown, but his aggressive expansionist views on acquiring Texas, Oregon, and California strike a receptive chord among Americans.
1845 - President Polk decides to treat Texas as a state, though it is still Mexican territory under international law. He sends a detachment of the U.S. army, led by Zachary Taylor, to the southwestern border of Texas to guard against "invasion" from Mexico.
1845 - The term, "Manifest Destiny" appears for the first time in the expansionist magazine the
Democratic Review, in an article by the editor, John O’Sullivan.
1845 - Polk commissions John Slidell to negotiate with Mexico for the purchase of Texas, New Mexico, and California.
1845 - Texas joins the Union as the twenty-eighth state.
1845 - Potato famines in Ireland begin to force great numbers of Irish immigrants to America. The migration will continue for the next several years with about 1.5 million Irish arriving.
1846 - 1850 

1846 - John Slidell reports that his negotiations with Mexico have been unsuccessful. Polk orders General Taylor to move the American troops further south, to a position near the left bank of the Rio Grande River, which has always been recognized as Mexican territory.
1846 - Mexican forces strike Fort Texas, a fort constructed by Taylor’s men. At the request of President Polk, Congress approves a
Declaration of War with Mexico. This war is yet another divisive issue between the North and South.
1846 - Oregon boundary dispute between U.S. and Britain is settled.
1846 -
Wilmot Proviso introduced in the House by David Wilmot, representative from Pennsylvania, which states, "neither slavery nor involuntary servitude shall ever exist in any part of territories that might be acquired from Mexico." This bill does not pass.
1847 - Abraham Lincoln takes his seat in the House of Representatives for Illinois.
1848 - The Senate, ending the war with Mexico, signs the Treaty of Guadalupe Hidalgo. The United States gains over 500,000 square miles, which include what shall become the states of California, Nevada, Utah, Arizona, New Mexico, and parts of Wyoming and Colorado. Texas is also conceded to the U.S., with its boundary at the Rio Grande. The U.S. pays $15 million.
1848 - The Free Soil movement begins, opposing the spread of slavery into the new territories.
1848 - Zachary Taylor, hero of the Mexican War, is elected President. Millard Fillmore is Vice President.
1849 - Thoreau publishes "
Civil Disobedience," an essay that grew out of his refusal to pay taxes supporting the Mexican War.
January 29, 1850 - U.S. Senator Henry Clay proposes the
Compromise of 1850
June 3 - 12, 1850 - Nine slave-holding states held the Nashville Convention of 1850, which resulted in the
Nashville Resolutions.
July 9, 1850 - President Taylor dies of cholera and Vice President Millard Fillmore assumes office.
September 9, 1850 -
New Mexico Territory is established without any restriction on slavery, to be decided by popular sovereignty. (Compromise of 1850)
September 9, 1850 -
State of California is admitted to the Union as a free state. (Compromise of 1850)
September 9, 1850 -
Utah Territory is established without any restriction on slavery, to be decided by popular sovereignty. (Compromise of 1850)
September 18, 1850 - The
Fugitive Slave Law was amended. (Compromise of 1850)
September 20, 1850 - The
Slave Trade in Washington City was suppressed. (Compromise of 1850)
1851 - 1855 

1851 - Uncle Tom’s Cabin, by Harriet Beecher Stowe, begins to appear as a serial in the anti-slavery publication, The National Era. The complete novel is published in 1852. It will sell over one million copies within a year. It will also be adapted as a stage play and thus reach even more people.
1852 - Senator Charles Sumner submits a resolution against the Fugitive Slave Act.
1852 - Senator Henry Clay dies.
Abraham Lincoln eulogizes his political idol.
1852 - Democrat Franklin Pierce is elected President over General Winfield Scott. William R. King becomes Vice President.
1853 -
Organic Act of 1853 created the Territory of Washington.
Gadsden Purchase for $10 million, Mexico agrees to cede a rectangular strip of territory along the present-day border of Arizona and New Mexico, which provides part of an ideal route for a railroad to the Pacific Ocean.
May 30, 1854 -
The Kansas-Nebraska Act passes Congress creates two new territories with "squatter" or "popular sovereignty" concerning the question of slavery. The act effectively repeals the Missouri Compromise. Opponents to this act form the basis of the new Republican Party. The party is made up of former Whigs, anti-slavery Democrats, and Free Soilers.
1854 - American foreign ministers in Cuba, who argue that Cuba must be annexed as a slave state, and that if Spain refuses to sell the island, it should be taken by force, draw up the “Ostend Manifesto”. When the document is published in the U.S., the public reaction is negative and the proposal falls from view.
1854 - The Know-Nothing Party holds its first meeting in Cincinnati.
1854 - "Bleeding Kansas” small-scale civil war erupts in Kansas between free-state and slave-state factions. Battles will continue until 1856 and beyond.
1855 - Frederick Douglass publishes his autobiography,
My Bondage, My Freedom
December 15, 1855 - A Kansas constitution convention adopts the Topeka Constitution that prohibited slavery and freedmen from the state. President Pierce ordered the legislature arrested for treason. Although the U.S. House approved the constitution, the Senate voted it down by two votes and Kansas was not admitted to the Union.
1856 - 1860 

1856 - "The Caning of Sumner” Charles Sumner, the outspoken anti-slavery senator from Massachusetts, gives a speech against the pro-slavery elements in the Senate; three days later, South Carolina representative Preston Brooks beats Sumner unconscious with a cane.
1856 - Democrat James Buchanan is elected President. Republican Frémont second, sweeping the Northern states. John C. Breckenridge is Vice President.
May 19-20, 1856 - U.S. Senator Charles Sumner delivered his
Crime Against Kansas speech.
May 22, 1856 - Congressman Preston Brooks caned Senator Charles Sumner on the floor of the U.S. Senate for his remarks of May 19-20 which impugned the character of his Brooks' cousin Senator Andrew P. Butler.
1857 - In the
Dred Scott v. Sanford decision, the Supreme Court declares that the Missouri Compromise is unconstitutional.
1857 - Hinton R. Helper publishes the Impending Crisis of the South he argues that slavery has impoverished Southern whites; it is banned in the South.
November 7, 1857 - Another Kansas constitution convention adopted the
Lecompton Constitution which enshrined slavery and protected the rights of slaveholders. Although it was supported by President Buchanan, Kansas voters overwhelmingly defeated it by 10,226 to 138.
1858 - Lincoln-Douglas debates the two candidates for representative of Illinois meet for a series of seven debates. Slavery is the main subject.
April 3, 1858 - A third Kansas constitutional convention adopted the
Leavenworth Constitution which was drafted by Free-staters. The document prohibited slavery, set a basic framework for the rights of women and document's Bill of Rights referred to "all men", making no distinction between whites and Negroes. Kansas voters approved it on May 18, 1858, but it was never accepted by Congress.
August 21, 1858 - First Lincoln-Douglas debate at Ottawa.
Mr. Douglas' opening speech,
Mr. Lincoln's speech and
Mr. Douglas' rejoinder
August 28, 1858 - Second Lincoln-Douglas debate at Freeport.
Mr. Lincoln's opening speech,
Mr. Douglas' speech and
Mr. Lincoln's rejoinder
September 15, 1858 - Third Lincoln-Douglas debate at Jonesboro.
Mr. Douglas' opening speech,
Mr. Lincoln's speech and
Mr. Douglas' rejoinder
September 18, 1858 - Fourth Lincoln-Douglas debate at Charleston.
Mr. Lincoln's opening speech,
Mr. Douglas' speech and
Mr. Lincoln's rejoinder
October 7, 1858 - Fifth Lincoln-Douglas debate at Galesburg.
Mr. Douglas' opening speech,
Mr. Lincoln's speech and
Mr. Douglas' rejoinder
October 13, 1858 - Sixth Lincoln-Douglas debate at Quincy.
Mr. Lincoln's opening speech,
Mr. Douglas' speech and
Mr. Lincoln's rejoinder
October 15, 1858 - Seventh Lincoln-Douglas debate at Alton.
Mr. Douglas' opening speech,
Mr. Lincoln's speech and
Mr. Douglas' rejoinder
1859 - John Brown’s raid on Harpers Ferry Brown leads a group of whites and blacks to attack the Federal arsenal. Brown is tried for conspiracy and then hanged.
July 29, 1859 - A fourth and final Kansas constitution convention adopted the
Wyandotte Constitution. The primary feature was that Kansas would be a free state. Democrat representatives refused to sign it.
October 4, 1859 - Kansas voters approved the new constitution by a vote of 10,421 to 5,530.
February 12, 1860 - U.S. House of Representatives passed a bill to admit Kansas into the Union by a vote of 134 to 73.
February 21, 1860 - Senator William H. Seward of New York introduced a separate bill on behalf of Kansas to the U.S. Senate. However, the Congressional session ended before a vote could be taken.
September 22, 1860 -
Texas Governor Sam Houston delivers an Anti-secession address at the Union Mass Meeting in Austin, Texas.
November 6, 1860 - Republican Abraham Lincoln elected President he wins with a clear majority of electoral votes but only a plurality of the popular votes. He defeats Breckenridge, Douglas, and Bell. Hannibal Hamlin is his vice-president.
December 3, 1860 - In his final
State of the Union, President James Buchanan stresses that states have no legal right to secede, yet neither does the Federal Government have the basis to prevent such an action.
December 13, 1860 - The Committee of Thirty-Three issued the
Southern Manifesto.
December 18, 1860 - The
Crittenden Compromise, a set of six amendments to the U.S. Constitution designed to formally institutionalize slavery and acts of nullification of state laws initiated to thwart the fugitive slave laws, was introduced by Senator John Crittenden.
December 20, 1860 -
South Carolina secedes from the Union.
December 26, 1860 - Fort Moultrie garrison transferred to Fort Sumter.
December 31, 1860 - The Crittenden Compromise was tabled by the U.S. Senate.