New England English
Eastern New England English encompasses Boston and Maine accents, and, according to some sources, the distinct Rhode Island accent. All Eastern New England English is famous for non-rhoticity, meaning it drops the "r" sound everywhere except before a vowel: thus, in words like "car", "card", "fear", and "chowder" (). The phrase "Park the car in Harvard Yard"—dialectally transcribed —is commonly used as a shibboleth, or speech indicator, for the non-rhotic Eastern New England dialect running from Boston north to Maine, and as far west as Worcester, which contrasts with the generally rhotic dialects elsewhere in North America. In all of Eastern New England, except Rhode Island, words like "caught" and "cot" are pronounced identically (both are often rounded, thus: ), because those two vowel sounds have fully merged. A phenomenon called Canadian raising occurs throughout Eastern New England, causing "writer" to have a different stressed vowel sound than "rider", and for the verb "house" to have a different vowel sound than the noun "house". and have relatively back starting positions. The "horse"–"hoarse" distinction is still present to some extent in some areas, as well as the "Mary"–"marry"–"merry" distinction in many speakers.
North American English regional phonology
Regional dialects in North America are historically the most strongly differentiated along the Eastern seaboard, due to distinctive speech patterns of urban centers of the American East Coast like Boston, New York City, and certain Southern cities, all of these accents historically noted by their London-like "r"-dropping (called non-rhoticity), a feature gradually receding among younger generations, especially in the South. The Connecticut River is now regarded as the southern and western boundary of the traditional New England accents, today still centered on Boston and much of Eastern New England. The Potomac River generally divides a group of Northeastern coastal dialects from an area of older Southeastern coastal dialects. All older Southern dialects, however, have mostly now receded in favor of a strongly rhotic, more unified accent group spread throughout the entire Southern United States since the late 1800s and into the early 1900s. In-between the two aforementioned rivers, some other variations exist, most famous among them being New York City English.