He was educated in Bristol in John Prior Estlin's school, before spending two years at Daventry Academy, his father's alma mater, 1787–89.
William Priestley was a mild-tempered and softly-spoken bohemian with long brown hair thrown back over his shoulders, and a passion for nature and music.
His father, writing to a friend, regretted that William's "temper [frame of mind] and high spirit [zest for life], will hardly suit trade.
[6] Despite William's disinclination towards office work, his father was prepared to pay for him to be articled to a merchant, though he baulked at the £1,000 Benjamin Vaughan had wanted.
He insisted on remaining at home, "Fairhill", as his parents fled, initially to ensure that the kitchen fire and candles were fully extinguished.
William assisted in managing the household, such as it was, and looked after the dietetic needs of his father, who suffered a bowel condition throughout his adult life, with episodes of severe diarrhoea.
[9] The noted Unitarian benefactress, Mrs Elizabeth Rayner, was impressed enough by William's practical care and filial concern for his father, to single him out for particular mention in her will.
He proposes to make his home here, and seeks to enjoy the rights of a citizen of France (a title which he prefers a hundred times to that of a king of an arbitrary state) – a member of a sovereign people that will greatly honour him by his adoption.
In the exercise of his duties as citizen and soldier, he will always keep in mind, and in his heart, the public spirit of the nation, the energy of its magistrates, and the lessons of his father.
[11]After a long speech by Tardiveau extolling the virtues of Joseph Priestley, interrupted fourteen times by applause, the Assemblée conferred letters of naturalization, and declared William an adopted son of France.
He visited Boston, and spent some time in Brattleboro, Vermont, with the also newly arrived family of William Wells, who was looking to buy a farm there.
On 3 February 1796, William Priestley married Margaret Foulke, "an amiable and sensible young woman" of Middle Paxton, at Paxtang Presbyterian Church, Harrisburg.
Mary Priestley's continuing ill-health would force the doctor to cancel planned excursions to New York and Boston, and return home early, at the end of May.
[19] The situation became even worse after December 1798, when his elder brother, Joseph Priestley Jr. left on a visit to England, not to return until August 1800.
During her husband's absence, Elizabeth Ryland-Priestley became involved with Thomas Cooper, perhaps romantically, but certainly by collaborating with him during his temporary editorship of the Sunbury and Northumberland Gazette from 20 Apr to 29 June 1799, writing several political essays for him.
[20] In September, Thomas Cooper printed a seditious handbill, which Joseph Priestley helped distribute around Point township, and across the Susquehanna at Sunbury.
On Tuesday 8 April 1800, William visited his father to discuss his plans, and express his concerns, in his brother's absence, about the relationship between Elizabeth Ryland-Priestley and Thomas Cooper.
Elizabeth persuaded a local physician, Dr William Cozens (1760-1836) to examine their oral discharges, and the flour boxes in the kitchen.
Elizabeth Ryland-Priestley's ridiculous and spiteful outburst was reported in the Reading Advertiser on Saturday 26 April 1800, preceded by gory accounts of cases of parricide in France by children anxious to demonstrate their revolutionary zeal.
[33] Leaving his pregnant wife and young son with his parents-in-law at Middle Paxton, William Priestley spent ten months trailing the banks of the Ohio and Mississippi, in search of a suitable place at which to settle.