In 1788, he as well as John Langdon and Peirce Long were delegates at the convention to determine what New Hampshire would decide about adopting the Federal constitution, which met in Exeter on Feb. 2. 10

U-S-History.com had this to say about John Pickering: "They enjoyed initial success by impeaching and removing from office one John Pickering, a federal judge in New Hampshire; Pickering was plagued by mental problems and probably needed to be removed from his position."

He was a Federalist Judge and a target in the political struggle between the Federalists and the then new Thomas Jefferson government. He was impeached by the Senate and removed from office.

"1805: The honourable John Pickering, LL D. died on Thursday the 13th day of April, in the sixty-eighth year of his age. Mr. Pickering was born at Newington, and was fitted for College by the Rev. Joseph Adams, minister of that place. He was graduated at Harvard College in 1761, and at first, turned his attention to divinity; but afterwards applied himself to the study of law. He was admitted to the bar and opened an office at Greenland, but shortly after removed to this town, and soon distinguished himself as an advocate and counsellor. In his early age he bacame a professor of religion, 'and was remarkably exemplary in all the walks of private, social, and public life.' The wardens and vestry of Trinity Church in Boston, invited him to settle there as a colleague with the Rev. Doctor Walter, but he declined accepting the invitation; preferring the profession of the law, in which he was already established. He supposed it would afford him as ample a field for the exercise of his talents, and give him as good an opportunity of promoting the cause of justice and humanity, as he should have in the ministry. He was candid and liberal in his practice, and faithful to his clients. He never refused to espouse the cause of the injured, notwithstanding in many instances, he had no prospect of pecuniary reward. Always endeavouring to promote the cause of Justice, he was considered an ornament to the bar. Conscious of the rectitude of his own intentions, he was slow to suspect others of being influenced by improper motives. 'His temper was placid, his manners gentle, his dispositions kind and benevolent, his habits, social. In conversation he was pleasant, instructive, and entertaining, and in his expressions remarkably chaste and elegant.' Although abounding in wit, he never indulged it to excite any unpleasant sensations in the bosoms of his friends. He was an honorary member of the Massachusetts Humane Society, and of the American Academy of Arts and Sciences; and the Government of Dartmouth College conferred on him the degree of Doctor of Laws.

The Confidence, placed in him by his fellow citizens, appears by their frequently electing him to some of the most important offices in their power to bestow. He was a delegate from this town to the convention for forming the State Constitution, which was adopted in 1783; and was a very influential member. The public are indepted to him for many important articles in that instrument.

He was likewise a delegate to the convention of this State, which adopted the Constitution of the United States, in 1788. His eloquence, and powers of reasoning probably had great effect, in procuring its adoption. For several years, he held a seat in the Legislature of the state, either as a representative of this town, a counsellor for the county, or senator for the district: In each of these offices, his only object was to promote the public good, and his skill in jurisprudence, enabled him to discern it. After the adoption of the Federal Constitution, Governor Langdon, who was elected a senator of the United States, resigned his office of Chief Magistrate of the state; Mr. Pickering as senior senator, presided the remainder of the year. In 1790, he was appointed Chief Justice of the Superior Court of Judicature, which office he held until the year 1795, when he was appointed Judge of the District Court of New Hampshire. His great legal knowledge, his integrity and eminent abilities qualified him for these judicial offices. But alas! the most brilliant talents are obscured when reason is dethroned. A few years previous to his decease, his rational faculties became impaired, and mental derangement succeeded. Whilst labouring under this afflicting dispensation of Providence, he was removed from office; notwithstanding the principles of law, do not hold a person amenable for his conduct, when deprived of reason. 'During his last confinement he had some lucid intervals, and at such times he invariably expressed his firm belief in the Christian religion, the fullest confidence in a future state, and his hope of happiness through the Redeemer.'" 10