[1] When his grandfather died in 1767, he inherited a large sum of money under the stipulations that he would change his name to the maternal surname Rowan, receive an Oxbridge education, and not visit Ireland before his 25th birthday.
With Lisburn MP, Todd Jones, he spoke not only of abolishing the proprietary boroughs (which gave the aristocracy and the government a stranglehold on the Irish Commons), but also of combining votes for Catholics with a secret ballot that would free them "from the too frequent tyranny" of the typically Protestant landlord".
[10] Neal had been lured into a Dublin brothel and then assaulted by Henry Luttrell (who, as Earl of Carhampton, later commanded Crown forces in the suppression of the 1798 Rebellion).
Hamilton Rowan publicly denounced Luttrell and published a pamphlet A Brief Investigation of the Sufferings of John, Anne, and Mary Neal in the same year.
An imposing figure at more than six feet tall, Hamilton Rowan's notoriety grew when he entered a Dublin dining club threatening several of Mary Neal's detractors, with his massive Newfoundland at his side, and a shillelagh in hand.
[11][12] In 1790, Hamilton Rowan joined the Northern Whig Club, and in November 1791 became a founding member of the Dublin Society of United Irishmen, working alongside famous radicals such as William Drennan, and Theobald Wolfe Tone.
Hamilton Rowan was arrested in 1792 for seditious libel when caught distributing Drennan's appeal to the disbanded Irish Volunteers to retain their weapons.
In 1793 in Edinburgh, Thomas Muir, whom Rowan and Drennan had feted in Dublin, with three other of his Friends of the People were sentenced to transportation to Botany Bay (Australia).
At the end of January 1794, notwithstanding representation by the renowned John Philpot Curran, and having refused to resign from the Society of United Irishmen as a condition for being allowed to go into exile, Rowan was sentenced to two years imprisonment and a substantial fine.
While imprisoned, Hamilton Rowan met the Reverend William Jackson, an Irish-born Anglican clergyman who was working as a spy for the French Committee of Public Safety.
Jackson, Tone, and others met in Hamilton Rowan's Newgate Prison cell to discuss the state of Ireland and the population's willingness to overthrow British rule.
While the jailer sat in the dining room of their home in Dublin, Hamilton Rowan excused himself to the bedroom, where he climbed down a rope made of knotted bed sheets to a waiting horse.
[20] In Wilmington, Hamilton Rowan led a very public life, enjoying the company of prominent Wilmingtonians such as Poole, John Dickinson, and Caesar A. Rodney, who later became Secretary of State under Jefferson.
Living in constant fear of summary deportation under the Alien and Sedition Acts, Hamilton Rowan took pains to socialise with both Federalists and Republicans, and he studiously avoided American politics.
The next year his business partner refused to make up the accounts for the calico mill, so Hamilton Rowan was forced to pay the bills out of pocket, and take over the entire operation himself.
Castlereagh's advisor Lord Hardwicke objected: not only would the minister's intervention "give greatest offence to the loyal", compared to the treatment of "the disaffected who are less well connected" it would "look like a flagrant piece of class distinction".
Following his last public appearance at a meeting in the Rotunda in Dublin "organized by the Friends of Civil and Religious Liberty" on 20 January 1829, he was lifted up by a mob and paraded through the streets.
[25] In 1831 in a letter to the Northern Whig (13 October 1831), he protested that he had "ever adhered to the principle which directed the original engagement of the United Irishmen", and proposed "the test of that Society, with some slight alterations, for the adoption of the friends of reform", emphasising, "an impartial representation of British subjects in Parliament", notably this time, with a reference of loyalty to the King.
Manuscript versions of the memoirs by various hands (again, in varying degrees of completion) are preserved in the Royal Irish Academy, The Public Record Office of Northern Ireland, and The Delaware Historical Society.