When William Sydney Porter had his first book, Cabbages and Kings (1904), published he had only six more years to live. But, with his identity hidden beneath the legendary pen name O. Henry, the fame of his short stories was already firmly...

Chief Obafemi Awolowo (1909-1987) was a Nigerian nationalist, a political leader, and a principal participant in the struggle for Nigerian independence. Obafemi Awolowo was born in Ikenné, Western State, Nigeria, on March 6, 1909. H...

Octavia Butler (born 1947) is best known as the author of the Patternist series of science fiction novels in which she explores topics traditionally given only cursory treatment in the genre, including sexual identity and racial conflict. ...

OCTAVIUS BROOKS FROTHINGHAM (26 November 1822-27 November 1895) was a religious and literary figure who reached his audience through the pulpit, press, published sermons, and biographies of leading figures. Most scholars today know him onl...

One of a set of twins, Odd Hassel was born May 17, 1897, in Kristiana (now Oslo), Norway. His father Ernst was a gynecologist. His mother, Mathilde Klaveness Hassel, raised her four sons and one daughter alone after her husband died when O...

The Germanic chieftain Odoacer (433-493), by deposing the Roman emperor Romulus Augustulus, is traditionally credited with ending the Western Roman Empire. Odoacer was born into a Germanic tribe, the Scirians, and was probably the younger ...

The English soldier and councilor Thomas Howard, 3d Duke of Norfolk (1473-1554), was a prominent figure in the government under Henry VIII. He led the conservative faction and opposed both Wolsey and Cromwell. Thomas Howard was born at a t...

Susumo Ohno's long and productive scientific career, influential in many areas of biology and genetics, was begun because of his love of horses. Ohno received his DVM from the Veterinary College of the Tokyo University of Agriculture and T...

Okomfo Anokye (active late 17th century) was an Ashanti fetish priest, statesman, and lawgiver. A cofounder of the Ashanti Kingdom in West Africa, he helped establish its constitution, laws, and customs. The original name of Okomfo Anokye ...

The Japanese statesman and politician Shigenobu Okuma (1838-1922) was one of the early leaders of the Meiji government. He later broke with it to become one of its most eloquent and respected critics. Born on Feb. 16, 1838, in Saga, the ca...

The wide range of eighteenth and nineteenth-century slave narratives—Anglo-African, French, Caribbean, North and South American, and Cuban—maps a long, diverse journey from slavery to freedom. The tradition roots twentieth-cent...

Ole Evinrude was born in Norway on April 19, 1877; five years later, his family emigrated to the United States and settled near Cambridge, Wisconsin. Interested in mechanics from an early age, Evinrude became an apprentice machinist at age...

Oliver Evans (1755-1819) was one of America's first and most important inventors. He made major contributions to the technology of flour milling and steam engines. Oliver Evans was born near Newport, Del. He was apprenticed to a wagon make...

The most influential Baptist minister of revolutionary South Carolina, Oliver Hart represents the union of evangelical religion and political rebellion. Born in Westminster Township, Bucks Country, Pennsylvania, to John and Eleanor Crispin...

The American politician Oliver Hazard Perry Throck Morton (1823-1877), as governor of Indiana during the Civil War, ably organized support for the Union. Oliver Perry Morton was born on Aug. 4, 1823, in Salisbury, Ind., but grew up in Ohio...

Although his father intended for him to become a businessman, Oliver Lodge instead became one of the pioneers of communication systems at the turn of the nineteenth century. Born on June 12, 1851, at Penkhull, Staffordshire, England, he wa...

Oliver Otis Howard (1830-1909), a general on the Union side in the American Civil War, was commissioner of the Freedmen's Bureau and helped establish an educational system for Southern African Americans. Oliver Otis Howard was born on Nov....

As a jurist and a legal writer, Oliver Wendell Holmes, Jr. (1841-1935), contributed mightily to the debate in the early 20th century concerning the role of law in a rapidly changing America. The U.S. government is based on a document writt...

The American inventor and manufacturer James Oliver (1823-1908) is noted for the invention of a cast-iron implement known as the Oliver chilled plow. James Oliver was born in Liddesdale, Roxburghshire, Scotland, on Aug. 28, 1823. The famil...

Olympia Snowe (born 1947) overcame the early deaths of both of her parents and her first husband to build a strong political career grounded in fiscal conservatism and to forge a fulfilling personal life based on a strong second marriage a...

Omar al-Mukhtar (ca. 1860-1931), national hero of Libya and member of the Senusy, a religious organization with administrative and military functions, led the anticolonial resistance in Cirenaica from 1923 to 1931, when he was captured by ...

Like many aspects of John Stuart Mill's life and work, his literary artistry remains a subject of enduring interest and lively disagreement. Few people would now question Mill's importance as spokesman for the humane liberal tradition in t...

John M. Opitz is renowned as one of the founders of clinical genetics. The Opitz G/BBB, Opitz-Kaveggia, and Smith-Lemli-Opitz syndromes all bear his name because of his research into the genetic roots of these pediatric abnormalities. Opit...

Geneticist George David Snell's pioneering research on the immune system in the 1930s and 1940s enabled medical science to develop the process of organ transplantation. Through skin grafts performed on mice at the Jackson Hole Laboratory, ...

The enormous production of the Franco-Flemish composer Roland de Lassus (1532-1594), over 1,200 works in all categories, and their extraordinarily high quality, make him one of the greatest masters of Renaissance music. Roland de Lassus, a...