There is an old truism in American politics that political parties go to New England to die. (The modern Democratic Party appears to be adhering to that model quite nicely.)
After 1800 the remaining Federalist presence was pretty much restricted to New England, and the Hartford Convention was its last gasp before the tidal wave rolled over it completely. I've always seen the Hartford Convention as a last ditch reaction to the Federalists' impotence -- and their incompetance in reading the pulse of the public.
The Federalist party died in 1804 when a bullet tore through Hamilton's abdomen. He had torn it apart by his attacks on Adams in the summer before the election in 1800.