He was descended from John Parker, of Bideford, Devon, who emigrated to America in 1629 and whose children settled in Charlestown.

After preparation at the Latin Grammar School, he entered Harvard at the age of fourteen and graduated in 1786 with high honors.

[1] In 1796, when he was twenty-eight, Parker was elected as a Federalist to the 5th Congress, but after one term of which little record of activity is available, he retired voluntarily to become United States Marshal for the Maine district (serving from March 5, 1799, to December 21, 1803).

He was shortly called upon to sit in the trial of T. O. Selfridge, charged with shooting the son of Benjamin Austin in a political quarrel.

His published works were confined to his judicial decisions and to a few orations, revealing a somewhat less florid style than that which characterized the times.

Parker rendered this kind of service, and many of his decisions came to be recognized as authoritative generally through the state and federal courts.

[5] In addition he rendered no small service by consolidating the reforms in the Massachusetts judicial system, instituted in the early years of the century.

Above the petinesses of party strife, free from affectation, at the same time both patient and gay, he carried into his public life the rectitude of an active and sincere religious conviction.