"The Adams Chronicles" by Jack Shepherd tells the story pretty well. The son was George Washington Adams (1801 -1829), eldest son of John Quincy Adams. He had loved and lost the affections of his first cousin Mary Catherine nee Hellem to his brother John Adams II (John married her in 1828). Other pressures from family concerning career expectations added to his misery. President JQA had lost the election for what would have been his second term as president and the family was moving out of the White House. GWA's mother Louisa summoned him to Washington from Braintree, MA by letter. GWA saw it as a summons to judgement. He took the ship Benjamin Franklin out of Providence and, about 3 AM, apparently stepped off the ship in the middle of Long Island Sound.
I recently read amessage from an Adams researcher that states there is a conspiracy theory circulating that GWA faked his own death with the help of his brother Charles Francis Adams and his father to escape the scandal and supposedly moved quietly to the western frontier of the Ohio Valley where he raised his own family. Great story, but no proof so far.