Why is there an I Street and a K Street but no J Street in Washington, D.C.?

Cecil replies:

That’s what you get for subjecting her to higher education — her first guess was a lot closer to the mark than her second. J is a late addition to the alphabet, having initially been introduced as an alternative form of I. It began to be used to signify our modern consonant J around 1600, but the two letters continued to be used interchangeably for years thereafter, e.g., jngeniously, ieweller. As late as 1820 some dictionaries still weren’t alphabetizing I and J words separately.

D.C. planner Pierre L’Enfant undoubtedly didn’t include a J Street because he considered I and J basically the same letter. (It certainly wasn’t because he disliked the statesman John Jay, as legend has it.) A similar confusion attended the letters U and V, which were also used interchangeably. The D.C. plan included both U and V streets, but using capital V to indicate both U and V on buildings (e.g., VNITED STATES POST OFFICE) survived until the 1930s, no doubt in imitation of such classical inscriptions as IVLIVS CAESAR.

From the Teeming Millions

Dear Cecil:

Your item on the letters I and J, U and V was not the last word (and no doubt what I have to add won’t be either). J and V were the consonantal forms of I and U, respectively (e.g., as in “juventus”). V in Latin was pronounced like W in English, and J was pronounced like Y in English.

— Stewart Colten, Arlington, Virginia

Sorry, Stewart. According to the Oxford English Dictionary, U and V were used “without clear distinction in value, each of them being used to denote either the vowel u or the consonant v. The practice with regard to the employment of the two forms varied considerably, but the general tendency was to write v initially and u in other positions, regardless of phonetic considerations.” The story with I and J is more complex, but the OED lists many instances of J being used as a vowel.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.