Timeline: The United States

1619
First Africans arrive in Virginia.

1640-1680
Beginning of large-scale introduction of African slave labor in the British Caribbean for sugar production.

1774
Connecticut and Rhode Island prohibit further importation of slaves (although Rhode Island merchants remain in slave trade to other colonies).

1776
Society of Friends (Quakers) abolishes slavery among members.

1777
Vermont Constitution prohibits slavery.

1780
Massachusetts Constitution adopted with freedom clause interpreted as prohibiting slavery.
Pennsylvania adopts gradual emancipation, freeing slaves born after 1780 upon their 28th birthday.

1784
Connecticut and Rhode Island pass gradual emancipation laws.

1788
Connecticut prohibits residents from participating in slave trade.

1789
U.S. Constitution ratified with clause equating slaves to 3/5ths of a white citizen and provision that slave trade would end within 20 years.

1793
Eli Whitney's invention of cotton gin sets stage for expansion of slavery in American South as short-staple cotton becomes economical product.

1798-1808
Decade of greatest importation of African slaves into U.S., totaling approximately 200,000.

1799
New York passes gradual emancipation law.

1800
U.S. citizens prohibited from exporting slaves.
Gabriel's conspiracy in Richmond, Virginia, seeks to overthrow slavery in Virginia.

1802
Slave boatmen plot rebellion along Roanoke River in Virginia.

1804
New Jersey passes gradual emancipation law.

1807
Great Britain abolishes slave trade.

1817
The American Colonization Society is founded, espousing the return of African Americans to Africa.

1819
U.S. law equates slave trading with piracy, punishable by death.

1820
The Missouri Crisis paralyzes national politics, as southerners and northerners argue over the admission of new slave states to the Union. Eventually, Missouri is admitted as a slave state, balanced by the admission of Maine as a free state. The Missouri Compromise also includes an agreement to bar slavery from northern federal territories -- a compromise that holds until 1854.
President James Monroe orders first U.S. Navy patrol against slave ships on West African coast

1822
The first settlers found the colony of Liberia, for freed African American slaves returning to Africa. Over the 1820s, some 1,400 blacks immigrate from the U.S. to the colony.
Denmark Vesey slave revolt plot uncovered in Charleston, South Carolina, and conspirators executed.
South Carolina passes Negro Seamen Acts requiring imprisonment of black sailors while in port to prevent their inciting slave revolts. Similar acts later passed in Alabama, Louisiana, and Cuba.
Pedro Blanco, former Spanish slave-ship captain, establishes slave factory at Lomboko on the Gallinas River in present Sierra Leone

1825
The Antelope Case: The U.S. Revenue Cutter Dallas seizes a slave ship, the Antelope, sailing under a Venezualan flag, with a cargo of 281 Africans, claimed by Portuguese and Spanish owners, in international waters. The U.S. Supreme Court hears five days of arguments before packed courtrooms.
March 16: John Marshall delivers a unaminous opinion declaring the slave trade a violation of natural law, meaning it can be upheld only by positive law.
But the ruling sets only 80% of the Africans free. U.S. law by this point defined the slave trade as piracy, but the court held that U.S. could not prescribe law for other nations -- and noted that the slave trade was legal as far as Spain, Portugal, Venezuela were concerned. Vessel was restored. Those Africans designated as Spanish property (numbering 39) the court recognized as property and sold into slavery on behalf of claimants. Portuguese claims the court found shakier, setting those Africans free.

1827
Jim Pembroke, a slave in Maryland, escapes and begins making his way northward, where he will rename himself James W.C. Pennington and rise to prominence within the African-American abolition movement.

1829
David Walker, a free African-American, publishes Appeal to the Coloured Citizens of the World, a radical pamphlet attacking slavery and the colonization movement. The Appeal invokes the rhetoric and spirit of the American Revolution, demanding: "See your Declaration, Americans!!! Do you understand your own language?"
Copies of the Appeal soon begin turning up in Southern ports, probably secretly distributed by free African-American seamen.
A year later, Walker is found dead near the doorway of his shop in Boston.

1830
The first annual Convention of the People of Colour assembles in Philadelphia to organize African-American opposition to slavery and to discrimination in the free states.

1831
January 1: William Lloyd Garrison begins publishing the Liberator.

August 22: In Southhampton County, Virginia, Nathaniel Turner leads a small slave uprising that quickly spreads to neighboring plantations and within a few days kills some 60 whites before local militia contain the revolt. In reprisal, scores of slaves are interrogated, tortured, and killed by panicked slaveholders. Turner himself eludes captures for a few months, but is eventually jailed and executed.

December: The Virginia legislature begins debating emancipation -- the last viable movement for abolition coming from within a southern state until the Civil War.

1833
William Lloyd Garrison and others found the American Anti-Slavery Society.

Connecticut passes the Black Law, barring blacks from attending private schools outside their resident towns without permission from town leaders. In Canterbury, CT, Prudence Crandell, a white school teacher, is prosecuted several times under this law.

1834
An anti-abolitionist mob sacks the home of prominent New York abolitionist Lewis Tappan, part of a savage riot that also destroys the home and church of African-American Episcopal Reverend Peter Williams.

1836
May 25: in response to petitions calling on Congress to abolish slavery in the District of Columbia, the House of Representatives implements the gag rule, automatically tabling abolitionist petitions. The policy is repeatedly renewed over the coming years.

1837
Abolitionist and editor Rev. Elijah P. Lovejoy is murdered by an anti-abolitionist mob in Alton, Illinois.

An Antislavery Convention of American Women meets in New York City with both black and white women participating.

African-Americans lose the right to vote in Pennsylvania (by amendment to the State Constitution) and Michigan (by state law). In New York, African-Americans petition the state legislature for voting rights.

1838
August 18: The U.S. Exploring Expedition sails from Hampton Roads, Virginia.

September: Frederick Baily escapes slavery, making his way from Baltimore to New York City, and from there to New Bedford, where he takes on a new name, Frederick Douglass.

A Philadelphia mob destroys the Pennsylvania Hall, where abolitionists have held meetings, then goes on a rampage burning and terrorizing African-American neighborhoods. Municipal authorities do nothing to halt the carnage.

Joshua R. Giddings of Ohio is elected to the U.S. House of Representatives, the first avowed abolitionist Congressman.

Rev. James W.C. Pennington, who would minister to the Amistad Africans, pastors an African Congregational Church at Newtown, Connecticut. In 1840 he moves to a new congregation in Hartford. In 1841 he publishes A Textbook of the Origin and History of the Colored People, the first history of its kind.

1839
June 12: HMS Buzzard escorts two American slave ships into New York, the brig Eagle and the schoonerClara, to be tried by American courts. Two weeks later, several more slavers arrive in New York, the Butterfly and the Catharine, manned by British naval officers as prizes of another royal ship on the Africa squadron. The British had already attempted to try the vessels in Sierra Leone before a mixed Anglo-Spanish commission adjudicating alleged slaving, but that commission had refused to try the vessels on the grounds they sailed under the American flag. At this point the British had escorted their prizes to New York, trying to force the Americans to enforce their laws against slave trading.

August 27: The Amistad is taken into New London.

November 13: The Liberty Party holds its first national convention in Warsaw, New York, proclaiming its anti-slavery program and nominating James C. Birney for President.
Among the Liberty Party's leading supporters is African-American abolitionist Henry Highland Garnet.

Theodore Dwight Weld publishes American Slavery as it is, a powerful indictment of slavery.

Garrisonians take control of the American Anti-Slavery Society and radicalize its platform, demanding the immediate abolition of slavery.

President Martin Van Buren orders U.S. Navy to resume West African patrols.

1840
January 19: The Wilkes Expedition claims part of Antarctica for the U.S.

Richard Henry Dana, Jr. publishes Two Years Before the Mast.

The Amistad Africans spend the year in jail.

Division in American Anti-Slavery Society over role of women weakens abolitionist efforts

1841
March 9: The U.S. Supreme Court upholds the freedom of the Amistad Africans.

November 7: African American slaves aboard the brig Creole revolt en route from Virginia to New Orleans. The rebels force the captain and crew to sail them to Nassau in the Bahamas. There British authorities take nineteen of the rebels into custody but free the remainder, England having abolished slavery in the British West Indies in 1833.

Frederick Douglass is hired by the Massachusetts Anti-Slavery Society as a full-time lecturer.

1842
January 18: Senator John C. Calhoun proposes a resolution calling on President Tyler to protest the British handling of theCreole incident. January 29: U.S. Secretary of State Daniel Webster issues a dispatch to the ambassador to Great Britain demanding indemnification for the freed slaves.

August 9: The U.S. and Great Britian sign the Webster-Ashburn Treaty, adjusting boundaries between the U.S. and Canada, and agreeing to cooperate on suppressing the slave trade.

In Boston, escaped slave George Lattimore is captured by bounty hunters -- the first in a series of confrontational fugitive slave cases. Abolitionists raise funds to purchase Lattimore's freedom.

In Philadelphia, a parade commemorating the abolition of slavery in the British West Indies is attacked by a proslavery mob.

1843
Sojourner Truth, an African-American woman who escaped from slavery, begins lecturing for abolitionism.

Rev. Henry Highland Garnet delivers a "Call to Rebellion" at the National Negro Convention in Buffalo, New York, exhorting African-Americans to resist slavery by means of armed rebellion (and holding up Cinque, among others, as heroes in the cause).

At the party convention for the Liberty Party in Buffalo, African-Americans participate directly for the first time, with Henry Highland Garnet serving on the nominating committee and two other black clergymen, Rev. Charles B. Ray and Rev. Samuel Ringgold, also playing prominent roles.

1848
Slavery entirely prohibited in Connecticut by state law.

1850
Compromise of 1850 admits California as free state, eliminates slave trade in District of Columbia, establishes Utah and New Mexico without restrictions on slavery, and requires return of fugitive slaves.

1854
Kansas-Nebraska Act repeals Missouri Compromise, allowing popular sovereignty to determine slave- or free-state status of territories seeking statehood, which increases sectional division within the U.S. and breaks down traditional two-party system, giving rise to Republican Party.

1857
Dred Scott decision by Supreme Court denies any possibility of citizenship for African Americans, imperils fugitive slaves, and sets back cause of abolition.

1859
John Brown's unsuccessful Harper's Ferry, Virginia, raid to incite slave rebellion heightens tension over slavery.

1860
20 December, South Carolina secedes from the Union after Abraham Lincoln's election as president, followed by 10 other states through May 1861.

1861
February, seceding states establish government of the Confederate States of America and create constitution endorsing slavery but prohibiting slave trade.

April, When Confederate forces fire on U.S. troops at Fort Sumter in Charleston Harbor, President Lincoln calls for troops to put down insurrection in the South, beginning the Civil War.

1862
September 22: President Lincoln issues Emancipation Proclamation, granting freedom to slaves in areas of the South in active rebellion on 1 January 1863.

1865
Slavery abolished in the U.S. by the 13th Amendment to the Constitution.

1866
14th Amendment to the Constitution defines a citizen as anyone born in the U.S. (except Native Americans) or naturalized, thereby extending all rights of citizenship to African Americans.
American Missionary Association founds Fisk University, among other black colleges established by this successor of the Amistad incident.

1875,
Civil Rights Act prohibits discrimination on juries and in public accommodations, except schools.
Blanche Kelso Bruce of Mississippi elected as first black U.S. Senator.

1883
Supreme Court Civil Rights Cases overturns Civil Rights Act and rules that 14th Amendment does not apply to privately owned facilities, including hotels, restaurants, and railroads, leading to segregated 'Jim Crow' laws, especially in the South.

1919
As part of his Universal Negro Improvement Association, Marcus Garvey establishes Black Star shipping lineJ.H. Rainey and former sailor and Civil War hero Robert Smalls of South Carolina are among first African Americans elected to U.S. Congress.

1944
First black officers commissioned in U.S. Navy.

1964
Congress passes Civil Rights Act.

1967
Thurgood Marshall appointed as first African-American Supreme Court Justice.

1971
Captain Samuel L. Gravely, Jr., promoted to become first African-American rear admiral in the U.S. Navy.