Portuguese seafarers round Cape Bojador on the West Coast of Africa and discover a large native population.

Portuguese sea captain Antam Goncalvez returns from exploring West Africa with two slaves, marking the first arrival of slaves in Europe from this region.

Nuno Tristao, a man under Goncalvez, captures 235 slaves, marking the commencement of the Portuguese slave trade.

Rhode Island becomes the first colony to prohibit slavery in all its forms.

In 1688, Quakers and Mennonites in Germantown (now Philadelphia, PA) protest against slavery, marking a pivotal moment in the early anti-slavery movement.

In 1693, the Philadelphia Monthly Meeting publishes an important document titled 'Exhortation & Caution to Friends Concerning the Buying or Keeping of Negroes', reflecting the Quaker stance against slavery.

In 1758, the Philadelphia Yearly Meeting establishes a committee to visit Quaker Friends who still own slaves, reflecting the growing recognition of the evil of slavery within the Society of Friends.

In 1759, Anthony Benezet's pamphlet 'Observations on the Inslaving, Importing and Purchasing of Negroes' is published in Germantown, marking the beginning of a series of influential anti-slavery works by one of the key figures in the 18th-century American abolitionist movement.

In 1772, John Woolman presents an anti-slavery certificate from Philadelphia at the London Yearly Meeting, furthering the recognition of the evil of slavery and influencing the Society of Friends to condemn the practice.

In 1775, the Society for the Relief of Free Negroes Unlawfully held in Bondage, also known as the Pennsylvania Abolition Society, held its first meeting in Philadelphia to work towards the abolition of slavery.

In 1780, Pennsylvania passes the Gradual Emancipation Act, marking a significant step towards the abolition of slavery in the state by providing a legal framework for the gradual liberation of enslaved individuals.

In 1784, Thomas Coke proposed an anti-slavery resolution during the 'Christmas Conference' of the Methodist Episcopal Church, highlighting early efforts within the Methodist movement to address the issue of slavery.

John Marrant's book, the first autobiography of a free black, is published in London.

Thomas Clarkson's work, quickly reprinted in the United States, becomes the most influential antislavery work of the late 18th century.

The Society for the Abolition of the Slave Trade is established in England to advocate for the end of the slave trade.

William Wilberforce becomes the Parliamentary leader and initiates a ten-year campaign to abolish Britain's slave trade.

The first American edition of Olaudah Equiano's autobiography, detailing his experiences as an enslaved African, including the Middle Passage, is published in London.

All 13 states approve the Constitution of the United States, leaving the question of slavery to the individual states.

The U.S. Congress passes the first fugitive slave law, mandating the return of escaped slaves to their owners.

Congress passes a law that prohibits American ships from transporting slaves to foreign countries from American ports.

Philadelphia free blacks submit a petition to Congress protesting against North Carolina laws that re-enslave blacks who were freed during the American Revolution.

A French resident in Philadelphia is summoned before local authorities for obtaining 130 French uniforms to support Toussaint L'Overture.

In 1800, Gabriel's Rebellion, led by enslaved African American Gabriel Prosser, took place in Virginia as a significant act of resistance against slavery.

Benjamin Rush assumes the presidency of the Pennsylvania Abolition Society, a prominent organization dedicated to the abolition of slavery.

In 1807, the British Parliament passed a law that prohibited British participation in the African Slave Trade, marking a significant step towards abolition.

The United States officially banned American involvement in the African Slave Trade in 1808. This led to the establishment of January 1st as a holiday in the black American community.

Chile passes the first antislavery law in the country.

The United States and England sign the Treaty of Ghent with the goal of stopping the slave trade.

The American Colonization Society was established in 1816 with the proposal of freeing slaves and sending them back to Africa as a compromise between antislavery activists and slavery supporters.

In 1818, Frederick Douglass, a future renowned orator and writer, escapes from slavery and makes his way to New York City.

In 1819, a federal law mandating the inspection of passenger conditions on ships was utilized by Quakers to monitor the slave trade at the Baltimore Port.

An agreement that prohibited slavery north of the 36°30´ parallel in the Louisiana Purchase territory, aiming to maintain a balance between slave and free states.

In 1822, Denmark Vesey, a free black, organizes an unsuccessful slave uprising in Charleston, SC.

In 1824, Liberia is established on the west coast of Africa by freed American slaves.

In 1827, John Russwurm and Samuel Cornish establish the first African American newspaper, Freedom's Journal, in New York. The paper circulates in various regions including 11 states, the District of Columbia, Haiti, Europe, and Canada.

In 1829, New Jersey Quaker born Benjamin Lundy establishes the first American anti-slavery newspaper, The Genius of Universal Emancipation, in Mt. Pleasant, Ohio. William Lloyd Garrison assists the paper from September 1829 until March 1830.

The first National Negro Convention was held in Philadelphia on September 15, 1830. The Convention aimed to protect the rights of freed Black Americans in the United States.

On January 1, 1831, William Lloyd Garrison published the first issue of 'The Liberator,' a prominent anti-slavery newspaper that played a significant role in the abolitionist movement.

From August 21 to October 30, 1831, the Nat Turner Rebellion occurred in Southampton County, Virginia, led by enslaved preacher Nat Turner. It was one of the most significant slave rebellions in the United States.

On April 20, 1832, Maria Stewart, a freeborn Black American political activist, started her journey as an abolitionist and feminist by addressing the African American Female Intelligence Society.

On December 6, 1833, William Lloyd Garrison founded the American Anti-Slavery Society in Philadelphia, which rapidly expanded to over 1300 chapters and 250,000 members within five years.

The Philadelphia Female Anti-Slavery Society was established by Lucretia Mott and Grace Bustill Douglass, among others, due to women being excluded from full membership in the AAAS.

The Slavery Abolition Act of Great Britain comes into force, leading to the emancipation of over 800,000 enslaved Africans in various British colonies including the Caribbean, South Africa, and Canada.

Britain abolishes slavery in its colonies on August 1, marking another significant moment for black Americans and abolitionists. This event becomes a holiday celebrating freedom and the end of slavery.

Anti-slavery petitions inundate congressmen's offices, prompting the House to enact the 'Gag Rule,' which automatically shelves these petitions without review. Former U.S. president John Quincy Adams and other anti-slavery advocates work to overturn this rule, with Adams facing potential censure.

Various abolitionist organizations come together to sue in the Commonwealth v. Aves case, where an enslaved person who moved to Boston with her enslaver is declared free and becomes a ward of the court.

The first Anti-slavery Convention of American Women takes place in New York, bringing together various women's anti-slavery groups. The Grimke sisters deliver speeches at this interracial association.

On November 7, 1837, abolitionist Elijah Lovejoy was tragically murdered, highlighting the violent opposition faced by those fighting against slavery.

On February 21, 1838, Angelina Grimke spoke before the Massachusetts legislature, advocating for both the abolition movement and women's rights.

Philadelphia Hall was set ablaze on May 17, 1838, by an anti-abolitionist mob, reflecting the tensions and violence surrounding the abolitionist cause during that period.

Cinque, who was captured from Sierra Leone and taken to Cuba, leads a revolt aboard La Amistad on July 1. The mutineers are later captured near Long Island, New York, and brought to New Haven, Connecticut.

Cinque and the other mutineers aboard La Amistad are captured on August 26 near Long Island, New York, after leading a revolt. They are then brought to New Haven, Connecticut.

An investigation hearing is held on August 29 for the Amistad Africans, including Cinque, who are charged with murder and piracy after the revolt aboard La Amistad.

On November 13, 1839, abolitionists announce the establishment of the Liberty Party, aiming to combat slavery through political means.

In January 1840, the Amistad Africans, including Cinque, appear in district court. The legal proceedings continue for the captured individuals.

The Amistad case, involving a slave revolt on the Spanish ship La Amistad, reaches the U.S. Supreme Court on February 20.

The Narrative of the Life of Frederick Douglass, an American Slave is published in Boston in 1845, marking the beginning of Frederick Douglass's prominent public career as a leading African American spokesperson in the 19th century.

In 1848, the Free Soil Party is established to oppose the spread of slavery into Western territories, reflecting the growing anti-slavery sentiment in the United States. Additionally, slavery is abolished in all French territories during the same year, marking a significant step towards emancipation.

Harriet Tubman escapes from slavery and becomes a prominent figure in the Underground Railroad, aiding many enslaved individuals to freedom. She also advocates for women's rights and equality.

The Compromise of 1850 includes the controversial Fugitive Slave Law, which mandates the capture and return of escaped slaves. This law sparks resistance from free blacks and abolitionists, leading to the formation of Vigilance Committees.

Federal marshals and slave hunters attempt to capture suspected fugitive slaves in Christiana, Pennsylvania, resulting in a confrontation with abolitionists. The subsequent trial of the accused individuals becomes a significant event in the abolitionist movement, with Thaddeus Stevens defending the defendants successfully.

Uncle Tom's Cabin, written by Harriet Beecher Stowe, was a novel that depicted the harsh realities of slavery in the United States. It played a significant role in shaping public opinion about slavery and is believed to have contributed to the start of the Civil War.

The Kansas-Nebraska Act was passed by Congress in 1854, leading to the repeal of the Missouri Compromise and allowing the territories to decide on the issue of slavery through popular sovereignty.

William Still and Passmore Williamson assist Jane Johnson and her children in escaping from their slave owner, leading to Williamson's imprisonment for several months. The case gains national attention and becomes a news story from August to November.

Pro-slavery U.S. Representative Preston Brooks assaults anti-slavery U.S. Senator Charles Sumner in the Senate chamber.

U.S. Supreme Court rules in the Dred Scott case, stating that slaveholders have rights over their human property nationwide and Black Americans are not U.S. citizens.

Abolitionist John Brown leads a failed biracial assault on the U.S. Armory at Harper’s Ferry, which results in his execution on December 2.

Abraham Lincoln of the antislavery Republican Party is elected president of the United States.

Samuel Hoar was a prominent lawyer and abolitionist who faced hostility and violence due to his anti-slavery beliefs.

President Lincoln signs the Emancipation Proclamation, declaring free slaves held in the Confederate states.

In 1864, Congress rules that black soldiers must receive equal pay for their service.

The Thirteenth Amendment to the Constitution officially bans slavery in the United States.

In 1870, the Fifteenth Amendment was passed, extending voting rights to Black men and marking the official end of the abolitionist movement.

In 1871, Pennsylvania, known for its abolition movement, grants the franchise to black men after thirty-two years of disfranchisement, becoming the home of the oldest and largest northern free black community during the Civil War.

A comprehensive encyclopedia edited by Junius P. Rodriguez focusing on the history of emancipation and abolition in the Transatlantic world.

Peter Grindal's book 'Opposing the Slavers' published in 2016 delves into the Royal Navy's efforts to combat the Atlantic slave trade, shedding light on the significant role played by naval forces in opposing slavery.

Seymour Drescher's book 'Pathways from slavery: British and colonial mobilizations in global perspective' was published in 2018, exploring the various pathways taken by British and colonial movements towards the abolition of slavery.

Manisha Sinha's review of David Brion Davis' book 'The Problem of Slavery in the Age of Revolution, 1770–1823' published in the American Historical Review.