Oliver Wendell Holmes, Sr. was one of Boston's most well-known authors in the mid-1800s. He was also a physician and medical reformer as well. He was born in Cambridge in 1809, and attended Harvard for undergrad, gained his MD from there, taught there, and was its dean at one point. Holmes was a member of the Fireside Poets, which included Henry Wadsworth Longfellow, William Cullen Bryant, John Greenleaf Whittier, and James Russell Lowell. His name was one of the biggest in the Boston literary community at the time, and much of what he wrote focused on Boston society. His poem "Old Ironsides," about the eminent scrapping of the USS Constitution, saved that ship from destruction and stirred the public to call for its preservation (you can visit the Constitution today at the Charlestown Navy Yard).
Holmes also coined the term "Boston Brahim" in his 1861 novel Elsie Venner; he entitled the first chapter "The Brahmin caste of New England." In the Indian caste system, the Brahmin caste is the highest, most elite segment of society; in New England, the term referred to the old, wealthy families of Boston. The term encapsulated the status of a family's roots, but also their dignity, their societal connections, their philanthropy, their appearance in society, etc. Usually the men in the family attended the same schools, usually the same families were marrying one another. Some examples of the family names (which you'll recognize if you're from the area) are Adams, Cabot, Coffin, Eliot, Emerson, Endicott, Forbes, Gardner, Holmes, Lawrence, Lowell, Otis, Parkman, Peabody, Phillips, Putnam, Quincy, Weld, Wigglesworth, and Winthrop.
You'll still hear the term "Boston Brahmin" today, and see it used much in literature. Know that it was indeed coined by an author!
Apparently they were also recognizable by their accent, of which you can watch an example below (Statler and Waldorf anyone?).