2,407 articles
Onondaga Council Fire
The Onondaga Council Fire is the central council fire of the Haudenosaunee Confederacy, kept by the Onondaga Nation near Syracuse, New York, where the Grand Council meets.
Open border
Open border: a border allowing free movement of people with little or no border control. Exists in practice via the Schengen area and similar zones; in philosophy, the position that states should not restrict immigration.
Operation Peter Pan
Operation Peter Pan (Operación Pedro Pan) airlifted 14,048 unaccompanied Cuban children to Miami from December 1960 to October 1962 via Catholic Welfare Bureau visa waivers, ending with the Missile Crisis.
Operation Wetback
Operation Wetback: 1954 INS mass deportation drive under Eisenhower, run by General Joseph Swing with Attorney General Brownell's plans, deporting over a million Mexicans while the Bracero guest-worker program expanded.
Opposition to immigration
Opposition to immigration: attitudes, movements, and policies favoring reduced migration. Spans U.S. nativism (Know-Nothings, Chinese Exclusion Act 1882, 1924 quota act), eugenics-linked restrictionism, and modern UK, French, and U.S. public opinion and enforcement politics.
Optional Practical Training
Optional Practical Training (OPT) is U.S. temporary work authorization for F-1 and M-1 foreign students, 12 months plus a 24-month STEM extension, regulated under 8 CFR 214.2 and upheld in Washington Alliance v. DHS.
Oralman
An oralman (Kazakh: оралман, from "to return") was the official legal status of ethnic Kazakhs who immigrated to Kazakhstan for permanent residence after independence in 1991.
Orang Asli
Orang Asli ("original people" in Malay) are the indigenous peoples of Peninsular Malaysia: 18 subgroups in the Negrito, Senoi, and Proto-Malay groups, about 227,900 people in 2025, governed by the Aboriginal Peoples Act 1954 with common-law customary land rights.
Orang Laut
Orang Laut, Malay for "sea people," are boat-dwelling maritime communities of the Thai-Malay Peninsula and Sumatra, historically pillars of the Srivijaya, Melaka, and Johor-Riau kingdoms.
Orange Order
Orange Order (Loyal Orange Institution): Protestant fraternal and parading organization founded after the Battle of the Diamond, 21 September 1795, County Armagh; named for William of Orange; Protestant-only membership; famous for Twelfth of July parades and the Drumcree dispute.
Order of the Eastern Star
Order of the Eastern Star, also called OES, is a Masonic-affiliated fraternal organization for Master Masons and their female relatives, founded in 1850 by Rob Morris, with the General Grand Chapter formed in 1876.
Order of the New Templars
Order of the New Templars (Ordo Novi Templi, ONT, Neutempler-Orden): occult-Ariosophic order founded around 1900 by Lanz von Liebenfels, promoting Aryan racial ideology under Templar symbolism; banned by the Nazis.
Organization
Organization: a social entity with differentiated roles and coordinated activities toward common objectives (formal and informal). Covers Weber's bureaucracy, comparative analysis, organizational design models, new organizational forms, and AI-driven organizational change.
Origin of the Palestinians
Origin of the Palestinians: ancestry of the Arabic-speaking people of historic Palestine. Traces Canaanite substrate, Arabization and Islamization, HLA genetic affinities with Jews and neighbors, and the modern al-Filastiniyyin identity.
Orla Guerin
Orla Guerin MBE (born 1966, Dublin) is the BBC's Senior International Correspondent, based in Istanbul. Formerly RTÉ and BBC postings in Jerusalem, Johannesburg, Islamabad, Cairo; MBE 2005; RTS Television Journalist of the Year 2018; Ukraine war coverage.
Oromo people
The Oromo people are Ethiopia's largest ethnic group, Cushitic-speaking (Afaan Oromo), known for the Gada governance system, the 16th-century Oromo expansion, and the Irreecha festival.
Osage Nation
The Osage Nation (Wahzhazhe, 𐓏𐓘𐓻𐓘𐓻𐓟) is a federally recognized Dhegiha Siouan tribe in Osage County, Oklahoma, seat Pawhuska. It purchased its 1.47-million-acre reservation in 1872, retains tribal ownership of the Osage Mineral Estate under the 1906 Act with headright royalties, endured the 1920s Reign of Terror, and has had a tripartite constitutional government since 2006.
Osama al-Rifai (أسامة الرفاعي)
Osama al-Rifai (أسامة الرفاعي), Syrian Sufi Sunni scholar born in Damascus in 1944, son of Abdul Karim al-Rifai, leader of Jamaat Zayd, exiled head of the Syrian Islamic Council, and Grand Mufti of Syria since 28 March 2025 under President al-Sharaa.
Ossetians (ирæттæ)
Ossetians (ирæттæ) are an Iranian-speaking people of the central Caucasus, the only descendants of the medieval Alans of Scytho-Sarmatian steppe stock, speaking the Eastern Iranian Ossetic language with Digor and Iron dialects.
Ostjuden
Ostjuden (German for Eastern Jews), Ostjude singular: term for East European, mainly Yiddish-speaking Jews in German-speaking Central Europe; a construct of German-Jewish self-definition and a central anti-Semitic stereotype from the nineteenth century onward.
Ota Benga
Ota Benga (c. 1883–1916), a Mbuti man from the Congo Free State, was exhibited at the 1904 St. Louis World's Fair and in the Bronx Zoo Monkey House in 1906 before settling in Lynchburg, Virginia, where he died by suicide in 1916.
Other Backward Class
Other Backward Classes (OBCs), or Socially and Educationally Backward Classes (SEBCs), are Indian caste communities listed by the Central Government for 27 percent reservation in central government jobs and educational institutions, subject to creamy layer exclusion, overseen by the constitutional NCBC.
Otherkin
Otherkin are people who identify as other-than-human while recognizing a human body; also called therians when identifying as Earth animals. Online-first subculture coined in 1990 on the Elfinkind Digest, with communities on Usenet, Facebook, Tumblr, and Discord.
Otis Pitts
Otis Pitts Jr. is an American community development leader in Liberty City, Miami, who attracted over $15 million in private investment and won a 1990 MacArthur Fellowship.
Overseas Chinese (海外华人)
Overseas Chinese (海外华人), also called the Chinese diaspora or Huaqiao/Huaren, are people of Chinese origin living outside mainland China, Hong Kong, Macau, and Taiwan. Estimates range from 10.7 million migrants to 60 million with descendants; the United States is the top destination.
Overseas Citizenship of India
Overseas Citizenship of India is a registration status for foreign citizens of Indian origin. It grants a lifelong visa and economic rights but does not confer Indian citizenship.
Overseas Filipinos
Overseas Filipinos, called the Filipino diaspora or Global Filipinos, are Filipinos living and working abroad, a diaspora the World Bank places at over 12 million.
Overseas Vietnamese
Overseas Vietnamese are people of Vietnamese birth or ancestry living outside Vietnam, a diaspora of about 3.4 million that grew after the 1975 fall of Saigon.
Owsley Stanley
Owsley Stanley (Augustus Owsley Stanley III, 1935–2011), nicknamed Bear, was the first large-scale underground LSD chemist, producing about 1.25 million doses 1965–1967, and the Grateful Dead's early sound engineer who conceived the 1974 Wall of Sound and left over 1,300 concert recordings.
Pachuco
Pachuco: Mexican American youth subculture of the 1930s-1950s, also called zoot suiters, defined by zoot suits, caló slang, and gang affiliation; marked by the 1943 Zoot Suit Riots and later Chicano cultural reclamation.