OK (also written as O.K., okay, or okeh) is an American English expression that has become globally recognized to indicate approval, acceptance, agreement, assent, or acknowledgment. It is widely used in both spoken and written language. The expression can function as different parts of speech in English, including an adjective ("He is O.K."), a noun ("He got my O.K."), an adverb ("He finished the job O.K."), and a verb ("He O.K.'d my plan").

Etymology and Historical Development

The origin of OK was long a subject of debate among linguists, and numerous theories were proposed. However, modern philological research traces the expression's origin to an abbreviation and wordplay fad that emerged in Boston in the late 1830s.

Early, Unsubstantiated Theories

Several theories regarding the origin of OK have been discredited over time due to a lack of supporting evidence:

Native American Origins

One of the most well-known theories suggested that the term derived from the Choctaw word okeh, meaning "it is so". This theory was notably adopted by U.S. President Woodrow Wilson, who used this spelling on official documents. Another theory proposed that the expression came from the initials of Old Keokuck, a Native American chief who assisted American allies during the Black Hawk War. Neither of these theories is supported by historical evidence.

Foreign Language Origins

The expression's origin has also been attributed to other languages. These include the French phrases aux quais ("at the wharves") or au qu'oui (an emphatic "yes"), the Finnish word oikea ("correct"), and the term Oberst Kommandant, supposedly used by a Prussian general. None of these claims are substantiated by concrete evidence.

Commercial and Individual Origins

Some theories linked the term's origin to commercial activities or specific individuals. These include the initials of the Orrins-Kendall Company, a cracker manufacturer during the Civil War; a freight agent named Obadiah Kelly, who supposedly initialed his bills of lading; or the fur trader John Jacob Astor, who was said to have marked bills with the letters. These narratives lack an evidentiary basis.

Humorous Misspelling Theory

Another common folk etymology claimed that the expression was an abbreviation of orl korrec, a Cockney pronunciation of "all correct". While this theory aligns with the playful nature of the term's actual origin, there is no direct evidence to support this specific derivation.

The "Old Kinderhook" Theory and Its Refutation

For a long period, the most widely accepted academic theory was put forth by linguist Allen Walker Read in 1941. According to this theory, OK originated as a slogan during the 1840 presidential campaign for Martin Van Buren. Van Buren was nicknamed "Old Kinderhook" after his birthplace of Kinderhook, New York, and his supporters formed the "Democratic O. K. Club". The theory posited that the rival Whig party launched a smear campaign, claiming that O.K. stood for oll korrect, a supposedly illiterate spelling of "all correct" by another Democratic leader, Andrew Jackson. According to this narrative, the "all correct" meaning emerged and spread during this political contest.

However, evidence that emerged in later years demonstrated that this theory was chronologically flawed. Research by Woodford A. Heflin revealed that OK was already in use with the "all correct" meaning before the political campaign began.

• Philadelphia Gazette (November 12, 1839): A report from this date noted that "o.k." was used in Wall Street as shorthand for "all correct".
• Baltimore Sun (February 24, 1840): An article from this date, preceding the main political activities, mentioned the expectation of an acknowledgment that a mint julep was "o. k. (all correct)".

These findings prove that the "all correct" meaning was not invented during the 1840 campaign; rather, the Democrats appropriated an already existing popular expression for their slogan.

The Abbreviation Fad and the "Oll Korrect" Origin

Current philological research establishes that the origin of OK lies in a humorous abbreviation fad that developed among Boston newspaper circles in the late 1830s. During this period, it became a popular trend, especially in the Boston Morning Post edited by Charles Gordon Greene, to use initials as shorthand for various phrases, often with a playful twist. Examples include:

• O.F.M. (our first men) 
• n.g. (no go) 
• S.P. (small potatoes) 
• O.W. (for "oll wright," a jocular spelling of "all right") 

Within this linguistic environment, OK emerged as a deliberate, humorous misspelling of "all correct" as 

"oll korrect". The first known recorded use of the expression appeared in the Boston Morning Post on March 23, 1839. In the article, the editor mentioned that an event would be "o.k. – all correct". Thus, the expression was not a product of illiteracy but rather a witty wordplay created by literate and humorous circles of the time.

Popularization and Place in Popular Culture

After its emergence in Boston, OK spread rapidly to other cities. Records show its use in New York and New Orleans by late 1839. While the 1840 political campaign did not invent the term, it was instrumental in its popularization and recognition on a national scale.

Spread to England

The use of OK in England began in the second half of the 19th century. It was recorded in a transatlantic telegraph message in 1866. The popularity of the American humorist Artemus Ward in the 1860s and the inclusion of the line "The O.K. thing to do" in the popular music hall song "Walking in the Zoo" (c. 1868) contributed to its spread among the public. The term's use in England increased further with the advent of sound films in the 1930s.

Institutional and Political Use

In 1858, a literary society named "the O.K." was founded at Harvard University. U.S. President Woodrow Wilson's practice of using "okeh" to approve documents, based on the incorrect Choctaw origin theory, gave the expression a degree of official standing.

Variants and Modern Usage

Over time, various forms of OK emerged.

• Verb Form: The first recorded use of OK as a verb, in the sense of "to approve" something, dates to 1888.
• Jocular Elongations: In the 1930s, whimsical and elongated forms such as "okie-doke" and "okie-dokie" gained popularity. Other variants like "oky-dory" and "okle-dokle" were also recorded.
• A-OK: In 1961, the expression "A-OK," allegedly used by astronaut Alan Shepard during his space flight, became a symbol of the space age. Although it was later revealed that the expression was not spoken by Shepard but attributed to him by a public affairs officer, the term has remained popular.

Today, OK has transcended the boundaries of English-speaking countries to become a global expression, adopted and understood in many different languages.