Also called "Transatlantic", this is an easily-recognized accent used in the first half of the 20th Century by the American upper class, movie stars and stage actors. Its distinctive sound is part of what defines the style of the Golden Age of Hollywood. Effectively the American counterpart to the British "Received Pronunciation", it's reminiscent of Brahmin Boston in many ways. It is in fact something of a British-American hybrid, and possesses three distinguishing characteristics:
- Lack of rhoticity, aka dropped "r"s ("mother", for instance, becomes "mothah")
- Strongly emphasized (hard, sharp) "T" sounds (as opposed the more American erosion of "T" into a "D"-like sound)
- Softened and stretched British-sounding vowels (a practice shared with the "Boston" accent)
The resulting sound is a slightly-nasal, clipped way of speaking that is neither completely British nor completely American.
Interestingly enough, "Mid-Atlantic" is not a "natural" accent; that is to say, it did not evolve among a common group of English speakers, who passed it on from generation to generation by exposure. Instead, it was effectly "engineered" into existence, intended to give American English an allegedly "native" but non-regional "upper-class" accent. It was passed on to new speakers almost exclusively by deliberate instruction. (Which is why it has its own page as a trope and only gets a cross-reference on American Accents.)
It spread in several ways -- it was taught in American boarding schools up until the 1950s, and even in many public school districts (it was a requirement for New York City teachers in the 1930s, for instance). But the most prominent avenue by which it was passed on was acting classes -- the book Speak With Distinction by Edith Skinner codified a particular version of "Mid-Atlantic" explicitly for use by stage actors, called "American Theater Standard". It became the default style of speaking for stage performers thanks to such instruction, and from there moved to radio and motion pictures. Some phonologists suggest it found a foothold in radio for some of the same reasons that it became common on the stage -- it carries well and clearly with only treble tones and no bass. It moved on into movies when talkies arrived simply because most new stars at the start of the era of talking pictures were recruited from the stage, and vocal coaches teaching the Skinner method or its close relatives were hired en masse to instruct existing Silent-era stars.
In general, the common use of Mid-Atlantic died out after World War II with the rise of the middle class and new, more realistic acting styles such as Method Acting. To modern ears it now sounds quaint and "old-fashioned". However, the "American Theater Standard" variant is still taught as the appropriate dialect for use in "classics" and "elevated texts" (such as the works of Shakespeare) in several dramatic schools in the United States, including Carnegie Mellon School of Drama, Julliard School, California Institute of the Arts, the Tisch School of the Arts, Webster University, and the Yale School of Drama.
- Cary Grant is perhaps the classic example in film.
- Katherine Hepburn
- Vincent Price was one of the last major stars to use the accent; then again, he was theatrically-trained.
- William Daniels -- it's particularly pronounced in his performance as John Adams in 1776.
- Carrie Fisher slips in and out of Mid-Atlantic in Star Wars:
Daahth Vadah. Ohnly you could be soh bohld.
- Fisher herself described it as a deliberate, if not successful, attempt to sound British, but the result, when she managed it, was distinctly Mid-Atlantic. Fortunately, she chose to drop it entirely by the time filming started on The Empire Strikes Back.
- Danny Kaye uses an exaggerated American Theater Standard accent to say "The theatah, the theatah, what's hahppened to the theatah?" at the start of the Choreography number in White Christmas.
- Singin' in the Rain includes several scenes where Lena Lamont and Don Lockwood are receiving instruction in American Theater Standard (the latter somewhat more successfully than the former) once their studio has switched to making talking pictures.
- Comic/musician Neal Gladstone uses a Mid-Atlantic Accent in his 1988 novelty song "Sleep Neat".
- The ushers and usherettes in the first act of A Day in Hollywood, A Night in the Ukraine slip in and out of the accent as appropriate as they take on various characters, character types, and performers from the Golden Age of Hollywood. One noteworthy instance is the song "Nelson", sung entirely in Mid-Atlantic by (allegedly) Nelson Eddy's long-time co-star Jeannette MacDonald.
- Franklin D. Roosevelt is probably the most familiar historical figure (to modern audiences) who spoke in Mid-Atlantic.
- The American upper class in general during the late 19th and early 20th century.
- Americans who have spent substantial time in England -- and some Brits who spend even longer in the United States -- may develop "natural" versions of Mid-Atlantic through extended exposure, but these are rarely if ever transmitted to offspring as a "native" way of speaking; in the vast majority of cases it had to be taught.