[1] After making a voyage to India as supercargo of the vessel in which he sailed, Cogswell studied law with Fisher Ames in Dedham,[2] and practised for a few years in Belfast, Maine.

[4] Two more years were passed in Europe, chiefly on the continent, in the principal capitals, and in the study of educational problems and bibliography.

He also contributed to Blackwood's Magazine (February, March 1819) two anonymous essays critically examining education in the United States.

In 1823, having resigned his chair in Harvard, he, in connection with George Bancroft, the historian, established Round Hill School at Northampton, Massachusetts.

Ill health and incompatibility with Southern culture led to Cogswell's resignation after only two years at Raleigh.

The Reverend Aldert Smedes was appointed Rector of the newly christened "St. Mary's College," a girls' school still thriving.

“He is,” said Irving, “a gentleman with whom I am on terms of confidential intimacy, and I know no one who, by his various acquirements, his prompt sagacity, his knowledge of the world, his habits of business, and his obliging disposition, is so calculated to give me that counsel, aid, and companionship, so important in Madrid, where a stranger is more isolated than in any other capital of Europe.” Cogswell received the appointment, and would probably have accepted it, but, Astor finding that he was likely to lose his invaluable services, made him superintendent of the new library.

[4] He also gave the Astor Library his own valuable series of works relating to bibliography, as he had before united with a friend in presenting Harvard with a rare cabinet of minerals and numerous botanical specimens.