| The colorful pseudoscience|
|Hating thy neighbour|
|Divide and conquer|
“”Whenever I hear anyone arguing for slavery, I feel a strong impulse to see it tried on him personally.
“”But, as it is, we have the wolf by the ear, and we can neither hold him, nor safely let him go. Justice is in one scale, and self-preservation in the other
Slavery is an institution in which one human being claims ownership of another, usually for the purposes of the "economic enrichment" of the owner through the forced labour of the slave. Slavery has a long and ignoble history, predating written records; said to be rare in hunter gatherer societies, slavery is thought to have been first made feasible 11,000 years ago during the neolithic revolution due to the invention of agriculture and food surplus storage.  By the time Denmark–Norway became the first nation to ban slavery, David Forsythe writes, "The fact remained that at the beginning of the nineteenth century an estimated three-quarters of all people alive were trapped in bondage against their will either in some form of slavery or serfdom."
The Atlantic slave trade
The most infamous incarnation of this practice was the Atlantic slave trade, in which Africans sold other Africans (often people captured in war, or stuck in debt peonage) to Europeans, who transported said people to work plantations in the Americas. The Atlantic slave trade was outlawed by the British in 1807, and the practice of slavery tapered out across the Americas over the next several decades. The last country in the Western Hemisphere to emancipate its slaves was Brazil in 1888. The last country to abolish slavery was Mauritania, which de jure abolished it in 1981, but as no laws were created to enforce the ban, only de facto abolished it in 2007. Despite this, up to 18% of the population of the country remain enslaved
This slave trade was by no means the first use of slaves in the world. Slavery had existed long before in Africa (and these slaves were the first to be sold to Europeans for working in America and elsewhere) and in other parts of the world, although often going by different names, such as "indentured workers." The practice of owning and treating people as property is thought to date back to Ancient Egypt and undoubtedly a less formal version has existed throughout the history of human civilization. Most ancient cultures (Egyptians, Romans, Greeks etc.) had one form of slavery or another. Ancient Rome was thought to have a massively high population of slaves, with the numbers being so high that they could be thought of as an ancient working class, although the estimates vary. Slavery in Ancient Greece and Ancient Rome was different from slavery in the Americas during the early modern era, as it was not openly racial (slaves could come from any ethnic group and become enslaved through either debt or being taken captive in war). While slavery was inherited in ancient times, owners often liberated slaves they personally knew and a slave could often earn money to buy himself. However, there were jobs (e.g. in the fields or mines) where slaves were literally worked to death and life expectancy was low. Through manumission and high death rates in other fields, the percentage of people born into slavery was never all that high (unlike in the antebellum South where next to all slaves were born into slavery and manumission was rare) as can be seen by late Republican era authors complaining about the rarity of Greek slaves - Greece had been conquered in the 2 century BC and most Greek slaves were (the descendants of) war captives.
One of the advantages of capitalism is that it requires the participation of free labor. In 1945, the Trinidadian historian Eric Williams argued that the European abolition of slavery in the 19th century was undertaken not in the name of compassion for the enslaved, but in order to meet the demands of new capitalist economies.
In the United States
“”I consider the labor of a breeding woman as no object, and a child raised every 2 years is of more profit than the crop of the best laboring man [...] providence has made our interests & duties coincide perfectly.
|—Thomas Jefferson, regarding constantly impregnating slaves to maximise profits.|
Slavery in the United States started out as indentured servants, primarily of Irish descent. As crop yields increased, so did the demand for labor. Anthony Johnson, a former indentured servant of African descent, filed a lawsuit to keep his indentured servant for the remainder of the servant's life, officially legalizing slavery in the Virginia Colony. Soon, many Europeans bought and sold Africans across the Atlantic to keep up with demand. Although the then non-Christian religion of the (African) slaves enabled their permanent and official enslavement through kidnapping as opposed to temporary de facto enslavement ("indentured servitude") through becoming indebted or criminals, their treatment was little different until Bacon's Rebellion in Virginia, 1676. Afterward sharply divergent treatment of British and African forced laborers was employed so that the former could be used to police and repress the latter, and both groups would be less likely to unite in rebellion in future. Virginian society transformed from a two-tiered class hierarchy to a three-tiered class-race one. 
The three-fifths clause in the Constitution (Article 1, Section 2, Paragraph 3) was about congressional representation as legally black slaves were regarded as having 0% rights, not even 60%. Southern states initially advocated that their slaves be counted as a full person so that they would have more representation in Congress while the North did not want them to count at all, as they were not legal citizens and could not vote. So they could settle and form a nation, the North suggested slaves count as half a person while the South wanted them to be 3/4ths; they settled on 3/5ths.
Areas in the United States where slavery was most common have unusually strong levels of race-based economic disparity, implying a direct heritage of modern economic problems among American Blacks due to slavery.
In 19th century Europe
Pope Leo XIII argued that the unfettered capitalism "lay upon the teeming masses of the laboring poor a yoke little better than that of slavery itself". This opposition would later become the basis for Distributism, and, to a lesser extent, the current Christian Democracy movement.
In the Third Reich
One of the most racist regimes ever, Nazi Germany relied heavily upon slave labor to do much farm, construction, and industrial work. Not sex — for such people were considered 'subhuman' even for use as prostitutes. Political prisoners and people from all over occupied Europe were forced into slavery. People worked under the threat of death in abominable conditions, often with beatings and hunger as companions. Among slave laborers were people that the Nazis gave temporary respites from quick murder in the Holocaust, only to be worked beyond the ability to survive.
Few of those slave laborers survived the war, and many were the cadavers exposed at Allied liberation of labor camps. For his role in procuring slaves from occupied countries, Fritz Sauckel was found guilty at the main Nuremberg Trial and put to death by hanging.
In the Bible
|—Jefferson Davis, President of the Confederate States of America, head stuck firmly up his ass|
Slavery is an excellent example of a social institution that is regarded as normal and acceptable in the Bible, but which is regarded today as an abomination. An interesting example of Christian, Jewish, and Islamic moral relativism, eh?
It is estimated that there are still upwards of 27 million people enslaved today. This number is higher than at any previous time in history, but abolitionists hope the practise can be wiped out in 30 years. This depends on the definition of slave, as some often count sex workers as slaves, particularly if they are immigrants that have been forced into the work to pay off debts to their contacts that helped them move country.
In the 21st Century, Quasi-State Legalised Slavery has returned in DAESH-held territory, where female captives, all non-Muslim minorities who have refused to convert to Islam, have been sold and distributed as sexual slaves. For the DAESH-aligned group Boko Haram, things are quite literally being done by the same book — the repeated kidnapping of women for use as sex slaves counts among their many noble deeds.
In the US, penal labor has been commonly used as forced labor. This has been allowed due to a loophole in the Thirteenth Amendment which allows forced labor to be used as a punishment for prisoners. Many Southern states turned many minor crimes into felonies in order to arrest African Americans and use them as a form of cheap labor. Modern corporations have greatly benefited from prisoners being used as low-cost labor.
Involuntary servitude has usually been seen as a form of slavery but this belief has commonly been abused by cranks. In 1916, Supreme Court ruled in the case Butler v. Perry that involuntary servitude could be permitted if it is a service to the state (like jury duty or military service); this case, though, dealt with a Florida law that forced citizens, many of them African Americans, to be forced to build roadways and likely went against the intent of the Thirteenth Amendment. Many anti-war activists and civil libertarians have contended that conscription is a form involuntary servitude and forces someone to kill, violating that person's rights of conscience. Various libertarians, conservatives, and moonbatty liberals have stated that compulsory schooling is a form of involuntary servitude and would prefer homeschooling or unschooling. Anti-vaxxers believe that mandatory vaccination violates their rights and forces them to vaccinate their children, which is against their beliefs. Tax protesters have called the income tax a form of slavery.
It is commonly claimed by those on the far-right that Islam is largely responsible for modern slavery, and that Islam is a particularly pro-slavery religion. As discussed in this article, no religion or ethnic group has a monopoly on slavery. Some majority-Muslim countries certainly have a problem with modern slavery, including Qatar, Uzbekistan, Pakistan, Mauritania, Sudan, and Bangladesh, but so do majority-Christian countries like Haiti, DR Congo, and Central African Republic, as well as India, Cambodia, China, North Korea, and others.
Slave-making ants practice a form of brood parasitism, abducting the young of other ants during raids, to increase the worker force of their own colony. It has been suggested the term be renamed pirate ants, which attempts to suggest impressment is somehow not just a specific type of slavery limited to the enslavement of sailors to serve on an enemy vessel.
In BDSM and psychology
Master slave relationships are common in consensual BDSM, though the use of this terminology can be quite offensive and be seen as trivializing or glorifying slavery. The practice of race play is also controversial and can cross over into detailed historical reenactment of punishments inflicted on slaves within a certain society that leave more accurate injuries than modern day civil war reenactments. 
As slavery is both a historical fact and widely considered a crime against humanity, various parties generate a large amount of woo as a post hoc justification to push their own agendas. This includes rightwing cranks, religious apologetics, extreme nationalists and 'cultural relativists' attempting to defend it, as well as various historical revisionists downplaying its role or its abuses.
Of the religious form, the Bible and Koran both allow for slavery. So how are these books "Good" when they clearly allow for something "Bad"? Well obviously the version in the book wasn't actually "slavery" at all, of course!
An example of the historical revision form of woo is Thomas Cahill's How the Irish Saved Civilization, which argues that Saint Patrick was the first abolitionist, and that as a result of his Christian mission Ireland became the first country on Earth to abolish slavery. In reality, scholars are very skeptical that St. Patrick ever existed, and they are even more skeptical that he ended slavery, given the numerous references to slaves in medieval Gaelic Irish law.
- Anti-slavery International, the oldest humanitarian organization which concentrates on freeing slaves across the globe.
- In 1857, it passed an act that said, "No person, because of descent, should be disqualified from becoming a citizen of the state." However, the act does not refer to one's status.
- "Slavery". Encyclopædia Britannica. https://www.britannica.com/topic/slavery-sociology.
- "David P. Forsythe". The Globalist. http://www.theglobalist.com/contributors/david-p-forsythe/.
- Anti-Slavery International 
- Eric Williams, Capitalism and Slavery, UNC Press Books, 1944.
- Isenberg, Nancy, White Trash - The 400-Year Untold History of Class in America (London, 2016) p.100
- Dan Hicks. "Ethnicity, Race and the Archaeology of the Atlantic Slave Trade".
- 2013 Heather A. O'Connell http://sf.oxfordjournals.org/content/90/3/713.abstract
- Leo XIII, Rerum novarum, 3.
- "Modern-Day Slavery", The New York Times. 2000 September 9.
- A tipping point in the fight against slavery?
- [http://www.bbc.co.uk/news/world-africa-22538888%7CBoko Haram timeline: From preachers to slave raiders ]
- Clarion Project
- The truth about Muslims and sex slavery - according to the Koran, rather than Isis or Islamophobes, The Independent
- See the Wikipedia article on Global Slavery Index.
- Global Slavery Index findings
- "Playing with Race", Daisy Hernandez, Color Lines, Dec 21, 2004