Historically in the context of slave societies of the Americas, a quadroon or quarteron was a person with one quarter African and three quarters European ancestry (or in the context of Australia, one quarter aboriginal ancestry).
Similar classifications were octoroon for one-eighth black (Latin root octo-, means "eight") and hexadecaroon for one-sixteenth black.
Governments of the time sometimes incorporated the terms in law defining rights and restrictions. The use of such terminology is a characteristic of hypodescent, which is the practice within a society of assigning children of mixed unions to the ethnic group which the dominant group perceives as being subordinate.  The racial designations refer specifically to the number of full-blooded African ancestors or equivalent, emphasizing the quantitative least, with quadroon signifying that a person has one-quarter black ancestry.
The word quadroon was borrowed from the French quarteron and the Spanish cuarterón, both of which have their root in the Latin quartus, meaning "a quarter".
Similarly the Spanish cognate cuarterón is sometimes used to describe someone whose racial origin is three-quarters white and one-quarter Indian, especially in Caribbean South America. 
Quadroon was used to designate a person of one-quarter African/Aboriginal ancestry, that is equivalent to one biracial parent (African/Aboriginal and Caucasian) and one white or European parent; in other words, the equivalent of one African/Aboriginal grandparent and three White or European grandparents.  In Latin America, which had a variety of terms for racial groups, some terms for quadroons were morisco or chino, see casta.
The term mulatto was used to designate a person who was biracial, with one pure black parent and one pure white parent, or a person whose parents are both mulatto.  In some cases, it was used as a general term, for instance on US census classifications, to refer to all persons of mixed race, without regard for proportion of ancestries.
The term octoroon referred to a person with one-eighth African/Aboriginal ancestry;  that is, someone with family heritage equivalent to one biracial grandparent; in other words, one African great-grandparent and seven European great-grandparents. As with the use of quadroon, this word was applied to a limited extent in Australia for those of one-eighth Aboriginal ancestry, as the government implemented assimilation policies on the Stolen generation.
Terceron was a term synonymous with octoroon, derived from being three generations of descent from an African ancestor (great-grandparent).  The term mustee was also used to refer to a person with one-eighth African ancestry.
The term sacatra was used to refer to one who was seven-eighths black or African and one-eighth white or European (i.e. an individual with one black and one griffe parent, or one white great-grandparent). 
The term mustefino refers to a person with one-sixteenth African ancestry.  The terms quintroon or hexadecaroon were also used.
|Black ancestry||Saint-Domingue||Guadeloupe/ Martinique|
During the antebellum period in the United States, abolitionists featured mulattoes and other light-skinned former slaves in public lectures in the North, to arouse public sentiments against slavery by showing Northerners slaves who were visually indistinguishable from them. This prevented them, the audience, from putting slaves into a category of " other", and not related to them in their society. 
The results of the colonization of the West Indies by the British, and the establishment of an African slave population there, was reflected in several 19th century English novels. These referred to mixed-race individuals in or from the West Indies by such terms as "mulatto", "quadroon", or "octoroon":
- Sanditon (1817), an unfinished novel by Jane Austen. Miss Lambe is described as a rich young woman from the West Indies, "about seventeen, half mulatto", i.e. a quadroon.
- Vanity Fair (1848), by William Makepeace Thackeray. Miss Rhoda Swartz ("Swartz" is a play on "swarthy", or the German word schwartze, i.e., dark or black) is described as "a rich woolly-haired mulatto" from the West Indies, whose father was a German Jew. Her appearance is mocked behind her back by her acquaintances in England, but her wealth makes her a prize in the marriage market of upper-class society. She eventually marries "a young sprig of Scotch nobility".
The figure of the "tragic octoroon" or " tragic mulatto" became a stock character of abolitionist literature in both the antebellum and Reconstruction eras. After the Civil War, this figure often represented social anxieties about the assimilation of mixed-race people in a changing society after the Civil War:
- The first American anti-slavery novel, Richard Hildreth's The Slave, featured a mixed-race character
- Harriet Beecher Stowe's bestselling 1852 novel Uncle Tom's Cabin
- The extremely popular 1859 play by Dion Boucicault, The Octoroon. 
In the stereotype versions, a light-skinned mixed-race child is raised as a white woman in her white father's household, until his bankruptcy or death leaves her reduced to a menial position or even sold into slavery. 
In some cases, she may be unaware of her full ancestry before being reduced to victimization, as in:
- Lydia Maria Child's short story, The Quadroons.  This stock character allowed abolitionists to reveal the sexual exploitation prevalent in slavery.
- The heroine of James Fenimore Cooper's 1826 novel The Last of the Mohicans, Cora, is the daughter of a quadroon or octoroon woman who married Cora's father, Lt. Colonel Munro. Col. Munro describes Cora's mother as "descended, remotely, from that unfortunate class who are so basely enslaved to administer to the wants of a luxurious people." When Col. Munro believes that a suitor, Duncan Heyward, has rejected Cora because of her mixed-race heritage, he chastises the young man: "You cast it on my child as a reproach! You scorn to mingle the blood of the Heywards with one so degraded — lovely and virtuous though she be?" Heyward assures Cora's father that this is not so ("Heaven protect me from a prejudice so unworthy of my reason!"), but inside he was "conscious of such a feeling, and that as deeply rooted as if it had been ingrafted in his nature."
- Richard Hildreth's 1836 novel The Slave; or, Memoirs of Archy Moore ("almost certainly the first anti-slavery novel published in America") is narrated by slave Archy Moore (mulatto son of his white owner, Colonel Moore). He marries a mixed-race slave, Cassy, who is sexually pursued by slave owners. 
- Lydia Maria Child's 1842 short story The Quadroons was printed in the abolitionist anthology The Liberty Bell
- Henry Wadsworth Longfellow's 1842 poem, The Quadroon Girl, has a planter knowingly selling his quadroon daughter to a slaver to be his sexual slave.
- Uncle Tom's Cabin (1852), a novel by Harriet Beecher Stowe, described Eliza and her son Harry as quadroons.
- Walt Whitman's 1855 poem Song of Myself refers to a "quadroon girl" who is sold at a slave auction.
- The Quadroon (1856) is a novel by Thomas Mayne Reid.
- The Octoroon, a play by Dion Boucicault adapted from Reid's The Quadroon, was first performed at New York City’s Winter Garden on December 12, 1859. The play describes the suffering by Zoe, an octoroon who learns about her African ancestry, which disrupts her life plans.
- Mary Mildred Williams, the first 'Poster Child', whose image was used by abolitionists to engender fears of 'white slavery'.
In the period after the American Civil War, Southerners also began writing about people of mixed race, as a way to explore the many contradictions in a postwar society based on a binary division of race. The topic continues to be a means to explore race in society. Authors in the early 20th century were writing against a background of legal racial segregation and disfranchisement of African Americans in the South. The successes of the 20th-century civil rights movement have not solved all racial problems. Authors in the 21st century are writing historical novels set in the 19th century that explore racial permutations.
- In Little Men (1868-1869), a novel by Louisa M. Alcott, Mr and Mrs Bhaer accept a quadroon boy to their school.
- George Washington Cable wrote about the Louisiana Creoles of mixed-race heritage; he explored issues for mixed-race mothers who had daughters with white men, and denied their parenthood to enable their light-skinned daughters to pass into the dominant white world in the post-war South. His most important works are Old Creole Days (1879), The Grandissimes (1880), and Madame Delphine (1881).
- In The Awakening (1899) by Kate Chopin, Pontellier's nurse is described as a quadroon.
- Désirée’s Baby (1893), a short story by Kate Chopin, features an apparently quadroon child born to two white parents; as the mother was adopted, the father assumes she has African ancestry and rejects her. He later burns a letter from his own mother; the reader learns that she was telling the son of her mixed-race ancestry.
- Charles W. Chesnutt, born free in Ohio and of mixed race, wrote some stories and novels featuring characters of mixed race and issues of the color line in the period following the American Civil War, such as The Wife of His Youth and Other Stories of the Color-Line (1899) and The House Behind the Cedars (1900).
- The titular character of James Weldon Johnson's book The Autobiography of an Ex-Colored Man (1912/1927) is a man of mixed race who can (and does) decide to pass for white.
- The Octoroon (1913) an American drama film produced by the Vitagraph Company.
- Aldous Huxley's Brave New World (1931) included some lower-caste social members described as octoroons.
- In William Faulkner's novel Absalom, Absalom! (1936), Charles Bon, said to have some portion of black ancestry, had a mixed-race son by his octoroon mistress in the 19th century.
- Zora Neale Hurston's novel Their Eyes Were Watching God covers the life of Janie Crawford, who was the product of her biracial mother's rape. Janie is particularly known for her long, straight hair, which is a white characteristic.
- Robert Penn Warren's 1955 novel Band of Angels deals with the historical theme of the seemingly white young woman who learns only after her planter father's death that she is the daughter of one of his slaves and will be sold to pay his debts.
- The Kyle Onstott novel, Mandingo, first published in 1957; republished in paperback and cut down in length by a third, it sold 5 million copies in the USA alone and was filmed in 1975 (also as Mandingo). There were 14 sequels and prequels published. The plot concerns slave breeding in the antebellum American South, mainly Alabama.
- In the 1971 historic film Quadroon, Coral is taught to impress young white men in time for New Orleans' annual Quadroon Ball of the early nineteenth century.
- John Irving's novel The World According to Garp (1976) features a character named Jillsy Sloper, who is described as 'the offspring of a white person and a quadroon—which made Jillsy an octoroon, or one-eighth Negro'.
- Anne Rice's novel The Feast of All Saints (1979) features the gens de couleur libres, "free people of color" in New Orleans before the Civil War. Her three novels in the series, Lives of the Mayfair Witches (1990 to 1994), also refer to mulatto and quadroon people in late 19th and early 20th-century New Orleans. The city had a high proportion of mixed-race people.
- In Love in the Time of Cholera (1985/1988 in English), by Gabriel Garcia Marquez and set during slavery time in Colombia, Florentino Ariza's mother Transito is described as a "freed quadroon".
- Benjamin January/Janvier is a free man of color of Louisiana, freed by his mother's white lover. He is the main character in Barbara Hambly's historical mystery series set in and around 1830s and later New Orleans; he is described as a griffe. Hambly's novels, published from 1997 to 2018, explore the city's complex caste system and the severe legal and social restrictions placed on people of color.
- A scene in Rabbit-Proof Fence, set in the nineteenth century, features an Australian government official explaining the government's plan to assimilate mixed-race Aboriginal children into white society in order to erase the Aboriginal ancestry through increased intermarriage. He uses the words quadroon and octoroon.
- In Island Beneath the Sea (2009), a novel set in late 18th-early 19th century Saint-Domingue ( Haiti) by Isabel Allende, the main character's daughter Rosette, is a free quadroon. Her mother is a free woman of color and former slave, and her father is a white Frenchman.
- In Archer, an animated comedy series on FX set in contemporary times and created by Adam Reed, the main character, Archer, refers to mentioning the word "quadroon" to his co-worker, Lana, in the past, and her "freaking out". The term is also used by a female character in the show, Pam, when talking about Lana's daughter, who is of mixed race. Archer describes their daughter as potentially being an octoroon in the third episode of Season 7.
- In Barkley, Shut Up and Jam: Gaiden, the character Balthios James, great-grandson of NBA player LeBron James, is referred to as an octoroon.
- Key and Peele is a comedic sketch show starring comedians Keegan-Michael Key and Jordan Peele. In the "Obama Meet and Greet" sketch, Peele (who is portraying Obama) refers to one of his supporters as an octoroon when greeting him.
- In Season 4 Episode 13 of How to Get Away With Murder, Viola Davis' character (Annelise Keating), refers to using the words "quadroon" and "octoroon" in her epic speech during her class-action lawsuit against the city to the Supreme Court judges.
- Kottak, Conrad Phillip. "Chapter 11: Ethnicity and Race," Mirror for Humanity a Concise Introduction to Cultural Anthropology. New York, NY: McGraw-Hill, 2009. 238. Print.
- "Definition". dle.rae.es.
- Carter G. Woodson and Charles H. Wesley, The Story of the Negro Retold, (Wildside Press, LLC, 2008), p. 44: "The mulatto was the offspring of a white and a black person; the sambo of a mulatto and a black. From the mulatto and a white came the quadroon and from the quadroon and a white the mustee. The child of a mustee and a white person was called the mustefino."
- Princeton University WordNet Search: octoroon
- Chisholm, Hugh, ed. (1911). Encyclopædia Britannica. 19 (11th ed.). Cambridge University Press. pp. 993–994. .
- "Quadroons, Octoroons, Sacatra, and Griffe".
- Frédéric Regent, Esclavage, métissage et liberté, Grasset, 2004, p.14
- Gérard Etienne, François Soeler, La femme noire dans le discours littéraire haïtien: éléments d'anthroposémiologie, Balzac-Le Griot, 1998, p.27
- Regent Frédéric, « Structures familiales et stratégies matrimoniales des libres de couleur en Guadeloupe au XVIIIe siècle », Annales de démographie historique 2/2011 (n° 122), p. 69–98
- Lawrence R. Tenzer, " White Slaves Archived 2011-11-09 at the Wayback Machine"
- Zanger, Jules (Spring 1966). "The "Tragic Octoroon" In Pre-Civil War Fiction". American Quarterly. 18 (1): 63–70. doi: 10.2307/2711111. JSTOR 2711111.
- Ariela J. Gross, What Blood Won't Tell: A History of Race on Trial in America, p. 61 ISBN 978-0-674-03130-2
- Kathy Davis. " Headnote to Lydia Maria Child's 'The Quadroons' and 'Slavery's Pleasant Homes'."
- Railton, Stephen. "Richard Hildreth's Slave". Uncle Tom's Cabin & American Culture. University of Virginia. Retrieved 4 August 2014.