Frederick Augustus Washington Bailey was born into slavery on the Eastern Shore of the Chesapeake Bay in Talbot County, Maryland. The plantation was between Hillsboro and Cordova; his birthplace was likely his grandmother's cabin.

At the age of 6, Frederick was separated from his grandparents and moved to the Wye House plantation, where Aaron Anthony worked as overseer.

After Anthony died in 1826, Douglass was given to Lucretia Auld, wife of Thomas Auld, who sent him to serve Thomas' brother Hugh Auld in Baltimore. Lucretia was essential in creating who Douglass was as she shaped his experiences, and had a special interest in Douglass from the time he was a child, wanting to give him a better life.

When Douglass was about 12, Hugh Auld's wife Sophia began teaching him the alphabet. From the day he arrived, she saw to it that Douglass was properly fed and clothed, and that he slept in a bed with sheets and a blanket.

When Douglass was hired out to William Freeland, he taught other slaves on the plantation to read the New Testament at a weekly Sunday school. As word spread, the interest among slaves in learning to read was so great that in any week, more than 40 slaves would attend lessons. For about six months, their study went relatively unnoticed. While Freeland remained complacent about their activities, other plantation owners became incensed about their slaves being educated. One Sunday they burst in on the gathering, armed with clubs and stones, to disperse the congregation permanently.

As a child, Douglass was exposed to a number of religious sermons, and in his youth, he sometimes heard Sophia Auld reading the Bible. In time, he became interested in literacy; he began reading and copying bible verses, and he eventually converted to Christianity.

In 1833, Thomas Auld took Douglass back from Hugh ("[a]s a means of punishing Hugh," Douglass later wrote). Thomas sent Douglass to work for Edward Covey, a poor farmer who had a reputation as a "slave-breaker." He whipped Douglass so regularly that his wounds had little time to heal. Douglass later said the frequent whippings broke his body, soul, and spirit. The 16-year-old Douglass finally rebelled against the beatings, however, and fought back. After Douglass won a physical confrontation, Covey never tried to beat him again.

Douglass first tried to escape from Freeland, who had hired him from his owner, but was unsuccessful. In 1837, Douglass met and fell in love with Anna Murray, a free black woman in Baltimore about five years older than he. Her free status strengthened his belief in the possibility of gaining his own freedom. Murray encouraged him and supported his efforts by aid and money.

On September 3, 1838, Douglass successfully escaped by boarding a northbound train of the Philadelphia, Wilmington and Baltimore Railroad.

Young Douglass reached Havre de Grace, Maryland, in Harford County, in the northeast corner of the state, along the southwest shore of the Susquehanna River, which flowed into the Chesapeake Bay. Although this placed him only some 20 miles (32 km) from the Maryland-Pennsylvania state line, it was easier to continue by rail through Delaware, another slave state. Dressed in a sailor's uniform provided to him by Murray, who also gave him part of her savings to cover his travel costs, he carried identification papers and protection papers that he had obtained from a free black seaman.

Douglass crossed the wide Susquehanna River by the railroad's steam-ferry at Havre de Grace to Perryville on the opposite shore, in Cecil County, then continued by train across the state line to Wilmington, Delaware, a large port at the head of the Delaware Bay.

From there, because the rail line was not yet completed, he went by steamboat along the Delaware River further northeast to the "Quaker City" of Philadelphia, Pennsylvania, an anti-slavery stronghold. He continued to the safe house of noted abolitionist David Ruggles in New York City. His entire journey to freedom took less than 24 hours. Frederick Douglass later wrote of his arrival in New York City: I have often been asked, how I felt when first I found myself on free soil. And my readers may share the same curiosity. There is scarcely anything in my experience about which I could not give a more satisfactory answer. A new world had opened upon me. If life is more than breath, and the 'quick round of blood,' I lived more in one day than in a year of my slave life. It was a time of joyous excitement which words can but tamely describe. In a letter written to a friend soon after reaching New York, I said: 'I felt as one might feel upon escape from a den of hungry lions.' Anguish and grief, like darkness and rain, may be depicted; but gladness and joy, like the rainbow, defy the skill of pen or pencil.

Once Douglass had arrived New York, he sent for Murray to follow him north to New York. She brought with her the necessary basics for them to set up a home. They were married on September 15, 1838, by a black Presbyterian minister, just eleven days after Douglass had reached New York. Douglass and Anna had five children: Rosetta Douglass, Lewis Henry Douglass, Frederick Douglass Jr., Charles Remond Douglass, and Annie Douglass (died at the age of ten).

The couple settled in New Bedford, Massachusetts (an abolitionist center, full of former slaves) in 1838.

After meeting and staying with Nathan and Mary Johnson, they adopted Douglass as their married name: Douglass had grown up using his mother's surname of Bailey; after escaping slavery he had changed his surname first to Stanley and then to Johnson. In New Bedford, the latter was such a common name that he wanted one that was more distinctive, and asked Nathan Johnson to choose a suitable surname. Nathan suggested "Douglass," after having read the poem "The Lady of the Lake" by Walter Scott, in which two of the principal characters have the surname "Douglas".

Douglass also joined several organizations in New Bedford, and regularly attended abolitionist meetings. He subscribed to Wm. Lloyd Garrison's weekly newspaper, The Liberator. Douglass later said that "no face and form ever impressed me with such sentiments [of the hatred of slavery] as did those of William Lloyd Garrison." So deep was this influence that in his last biography, Douglass confessed "his paper took a place in my heart second only to The Bible". Garrison was likewise impressed with Douglass, and had written about his anti-colonialist stance in The Liberator as early as 1839.

Douglass thought of joining a white Methodist Church, but was disappointed, from the beginning, upon finding that it was segregated. Later, he joined the African Methodist Episcopal Zion Church, an independent black denomination first established in New York City, which counted among its members Sojourner Truth and Harriet Tubman. He became a licensed preacher in 1839, which helped him to hone his oratorical skills. He held various positions, including steward, Sunday-school superintendent, and sexton.

In 1840, Douglass delivered a speech in Elmira, New York, then a station on the Underground Railroad, in which a black congregation would form years later, becoming the region's largest church by 1940.

In 1841, Douglass first heard Garrison speak at a meeting of the Bristol Anti-Slavery Society. At another meeting, Douglass was unexpectedly invited to speak. After telling his story, Douglass was encouraged to become an anti-slavery lecturer. A few days later Douglass spoke at the Massachusetts Anti-Slavery Society's annual convention, in Nantucket. Then 23 years old, Douglass conquered his nervousness and gave an eloquent speech about his rough life as a slave.

The couple then moved to Lynn, Massachusetts, in 1841.

While living in Lynn, Douglass engaged in early protest against segregated transportation. In September 1841, at Lynn Central Square station, Douglass and friend James N. Buffum were thrown off an Eastern Railroad train because Douglass refused to sit in the segregated railroad coach.

In 1843, Douglass joined other speakers in the American Anti-Slavery Society's "Hundred Conventions" project, a six-month tour at meeting halls throughout the Eastern and Midwestern United States. During this tour, slavery supporters frequently accosted Douglass. At a lecture in Pendleton, Indiana, an angry mob chased and beat Douglass before a local Quaker family, the Hardys, rescued him. His hand was broken in the attack; it healed improperly and bothered him for the rest of his life.

Douglass's best-known work is his first autobiography, Narrative of the Life of Frederick Douglass, an American Slave, written during his time in Lynn, Massachusetts and published in 1845.

Douglass's friends and mentors feared that the publicity would draw the attention of his ex-owner, Hugh Auld, who might try to get his "property" back. They encouraged Douglass to tour Ireland, as many former slaves had done. Douglass set sail on the Cambria for Liverpool, England on August 16, 1845. He traveled in Ireland as the Irish Potato Famine was beginning. The feeling of freedom from American racial discrimination amazed Douglass: Eleven days and a half gone and I have crossed three thousand miles of the perilous deep. Instead of a democratic government, I am under a monarchical government. Instead of the bright, blue sky of America, I am covered with the soft, grey fog of the Emerald Isle [Ireland]. I breathe, and lo! the chattel [slave] becomes a man. I gaze around in vain for one who will question my equal humanity, claim me as his slave, or offer me an insult. I employ a cab—I am seated beside white people—I reach the hotel—I enter the same door—I am shown into the same parlour—I dine at the same table—and no one is offended ... I find myself regarded and treated at every turn with the kindness and deference paid to white people. When I go to church, I am met by no upturned nose and scornful lip to tell me, 'We don't allow niggers in here!' He also met and befriended the Irish nationalist Daniel O'Connell, who was to be a great inspiration.

Douglass spent two years in Ireland and Great Britain, where he gave many lectures in churches and chapels. His draw was such that some facilities were "crowded to suffocation". One example was his hugely popular London Reception Speech, which Douglass delivered in May 1846 at Alexander Fletcher's Finsbury Chapel. Douglass remarked that in England he was treated not "as a color, but as a man".

After returning to the U.S. in 1847, using £500 (equivalent to $46,030 in 2019) given him by English supporters, Douglass started publishing his first abolitionist newspaper, the North Star, from the basement of the Memorial AME Zion Church in Rochester, New York.

In 1847, Frederick Douglass explained to Garrison, "I have no love for America, as such; I have no patriotism. I have no country. What country have I? The Institutions of this Country do not know me—do not recognize me as a man".

In 1848, Douglass was the only African American to attend the Seneca Falls Convention, the first women's rights convention, in upstate New York. Elizabeth Cady Stanton asked the assembly to pass a resolution asking for women's suffrage. Many of those present opposed the idea, including influential Quakers James and Lucretia Mott. Douglass stood and spoke eloquently in favor of women's suffrage; he said that he could not accept the right to vote as a black man if women could not also claim that right. He suggested that the world would be a better place if women were involved in the political sphere. In this denial of the right to participate in government, not merely the degradation of woman and the perpetuation of a great injustice happens, but the maiming and repudiation of one-half of the moral and intellectual power of the government of the world. After Douglass's powerful words, the attendees passed the resolution.

In September 1848, Douglass published an open letter addressed to his former master, Thomas Auld, berating him for his conduct, and inquiring after members of his family still held by Auld.

Like many abolitionists, Douglass believed that education would be crucial for African Americans to improve their lives. This led Douglass to become an early advocate for school desegregation. In the 1850s, Douglass observed that New York's facilities and instruction for African-American children were vastly inferior to those for whites. Douglass called for court action to open all schools to all children. He said that full inclusion within the educational system was a more pressing need for African Americans than political issues such as suffrage.

Meanwhile, in 1851, Douglass merged the North Star with Gerrit Smith's Liberty Party Paper to form Frederick Douglass' Paper, which was published until 1860.

On July 5, 1852, Douglass delivered an address to the ladies of the Rochester Anti-Slavery Sewing Society. This speech eventually became known as "What to the Slave Is the Fourth of July?"; one biographer called it "perhaps the greatest antislavery oration ever given".

In 1855, Douglass published My Bondage and My Freedom.

On March 12, 1859, Douglass met with radical abolitionists John Brown, George DeBaptiste, and others at William Webb's house in Detroit to discuss emancipation.

Douglass and the abolitionists argued that because the aim of the Civil War was to end slavery, African Americans should be allowed to engage in the fight for their freedom. Douglass publicized this view in his newspapers and several speeches. In August 1861, Douglass published an account of the First Battle of Bull Run that noted that there were some blacks already in the Confederate ranks.

President Lincoln's Emancipation Proclamation, which took effect on January 1, 1863, declared the freedom of all slaves in Confederate-held territory.

Douglass conferred with President Abraham Lincoln in 1863 on the treatment of black soldiers, and with President Andrew Johnson on the subject of black suffrage.

During the U.S. Presidential Election of 1864, Douglass supported John C. Frémont, who was the candidate of the abolitionist Radical Democracy Party. Douglass was disappointed that President Lincoln did not publicly endorse suffrage for black freedmen. Douglass believed that since African-American men were fighting for the Union in the American Civil War, they deserved the right to vote.

The post-war (1865) ratification of the 13th Amendment outlawed slavery. The 14th Amendment provided for citizenship and equal protection under the law. The 15th Amendment protected all citizens from being discriminated against in voting because of race.

In a speech delivered on November 15, 1867, Douglass said: "A man's rights rest in three boxes. The ballot box, jury box and the cartridge box. Let no man be kept from the ballot box because of his color. Let no woman be kept from the ballot box because of her sex".

In an effort to combat these efforts, Douglass supported the presidential campaign of Ulysses S. Grant in 1868.

After the Civil War, when the 15th Amendment giving Blacks the right to vote was being debated, Douglass split with the Stanton-led faction of the women's rights movement. Douglass supported the amendment, which would grant suffrage to black men. Stanton opposed the 15th Amendment because it limited expansion of suffrage to black men; she predicted its passage would delay for decades the cause for women's right to vote. Stanton argued that American women and black men should band together to fight for universal suffrage, and opposed any bill that split the issues.

In 1870, Douglass started his last newspaper, the New National Era, attempting to hold his country to its commitment to equality.

After the midterm elections, Grant signed the Civil Rights Act of 1871 (also known as the Klan Act), and the second and third Enforcement Acts.

In 1872, Douglass became the first African American nominated for Vice President of the United States, as Victoria Woodhull's running mate on the Equal Rights Party ticket. He was nominated without his knowledge. Douglass neither campaigned for the ticket nor acknowledged that he had been nominated.

Douglass was presidential elector at large for the State of New York, and took that state's votes to Washington, D.C..

The Freedman's Savings Bank went bankrupt on June 29, 1874, just a few months after Douglass became its president in late March.

On April 14, 1876, Douglass delivered the keynote speech at the unveiling of the Emancipation Memorial in Washington's Lincoln Park. In that speech, Douglass spoke frankly about Lincoln, noting what he perceived as both positive and negative attributes of the late President. Calling Lincoln "the white man's president", Douglass criticized Lincoln's tardiness in joining the cause of emancipation, noting that Lincoln initially opposed the expansion of slavery but did not support its elimination. But Douglass also asked, "Can any colored man, or any white man friendly to the freedom of all men, ever forget the night which followed the first day of January 1863, when the world was to see if Abraham Lincoln would prove to be as good as his word?" Douglass also said: "Though Mr. Lincoln shared the prejudices of his white fellow-countrymen against the Negro, it is hardly necessary to say that in his heart of hearts he loathed and hated slavery ...".

In 1877, Douglass visited Thomas Auld, who was by then on his deathbed, and the two men reconciled.

In 1881, after the Civil War, Douglass published Life and Times of Frederick Douglass, which he revised in 1892.

Anna his wife, died in 1882.

Douglass also continued his speaking engagements and travel, both in the United States and abroad. With his new wife, Helen, Douglass traveled to England, Ireland, France, Italy, Egypt and Greece from 1886 to 1887. Douglass also became known for advocating Irish Home Rule and supported Charles Stewart Parnell in Ireland.

At the 1888 Republican National Convention, Douglass became the first African American to receive a vote for President of the United States in a major party's roll call vote.

President Harrison appointed Douglass as the United States's minister resident and consul-general to the Republic of Haiti and Chargé d'affaires for Santo Domingo in 1889.

Douglass resigned the commission in July 1891.

In 1892, Douglass constructed rental housing for blacks, now known as Douglass Place, in the Fells Point area of Baltimore. The complex still exists, and in 2003 was listed on the National Register of Historic Places.

On February 20, 1895, Douglass attended a meeting of the National Council of Women in Washington, D.C. During that meeting, he was brought to the platform and received a standing ovation. Shortly after he returned home, Douglass died of a massive heart attack. He was 77. Douglass' coffin was transported back to Rochester, New York, where he had lived for 25 years, longer than anywhere else in his life. He was buried next to Anna in the Douglass family plot of Mount Hope Cemetery, and Helen joined them in 1903.

In the 21st century, historical plaques were installed on buildings in Cork and Waterford, Ireland, and London to celebrate Douglass's visit: the first is on the Imperial Hotel in Cork and was unveiled on August 31, 2012; the second is on the facade of Waterford City Hall and was unveiled on October 7, 2013. It commemorates his speech there on October 9, 1845. The third plaque adorns Nell Gwynn House, South Kensington in London, where Douglass stayed with the British abolitionist George Thompson. A plaque on Gilmore Place in Edinburgh marks his stay there in 1846.

Douglass married again, to Helen Pitts, a white suffragist and abolitionist from Honeoye, New York. Pitts was the daughter of Gideon Pitts Jr., an abolitionist colleague and friend of Douglass.