He was one of the most colourful and erratic characters in 19^th century Irish history. Thomas Francis Meagher was born to a wealthy Waterford merchant family in 1823. He was educated by the Jesuits at Clongowes wood and later at Stonyhurst in England, where he replaced his Irish accent with a clipped upper class English drawl – something that was to alienate many of his fellow-countrymen in the years that followed.

His involvement with the Young Ireland movement in the 1840s led to his falling out with Daniel O’Connell and a drift towards militancy. This culminated in the farcical 1848 rebellion – but before that dismal revolutionary failure Meagher had conferred on the Irish nation perhaps his most abiding legacy – the green, white and orange tricolor. He had been gifted the flag on a visit to France and its use in the 1916 rising copper-fastened its status as the flag of the Irish republic.

His involvement in the 1848 rebellion led to a sentence that he was to suffer the barbaric punishment of being ‘hanged, drawn and quartered’ – this was later commuted to transportation to Van Diemen’s Land, or Tasmania. Initially Meagher opted for a ‘ticket of leave’ arrangement, whereby he was given considerable freedom on a promise not to attempt to escape from captivity there. In 1852 he abruptly surrendered his ticket of leave and escaped to the USA where, arguably, he made a greater contribution to American history than he did to that of his native country.

His most significant impact came after the outbreak of the Civil War. Taking over command of the Irish brigade from Michael Corcoran he proved to be an excellent recruiter for the Union army. His backing of the Union had not been a given, initially he had been an advocate of states rights and a supporter of the South, sharing many of the views of his friend John Mitchel. Ultimately they parted company over the issue of slavery and Meagher committed himself to the Union cause.

Knowing his target market well one of General Meagher’s recruiting posters read –‘The Cotton Lords and Traitor Allies of England Must Be Put Down Once and for All.’ To his detractors, of whom there were many, Meagher was a self important and pompous alcoholic. But to his troops he was their General, ‘Meagher of the Sword’. His reputation was sealed by an iconic engraving of the celebrated American artists Currier and Ives in which he was depicted on horseback leading the Irish Brigade into the Battle of Fair Oaks in June 1862

When the great Southern commander, Robert E.Lee, marched his forces north into Maryland in the fall of 1862, Meagher’s Irish Brigade was badly mauled at the infamous Battle of Antietam. Meagher had fallen off his horse in the fighting – his detractors claimed that he had been drunk at the time. This was followed by an even more bloody encounter with the Confederacy near the small town of Fredericksburg, Virginia, in December, 1862.

Most of the Brigade’s regimental banners had already been shot to pieces. But Meagher insisted that they go into the fight carrying some symbol of their nationality. A boxwood hedge was raided and bunches of leaves of the evergreen plant were distributed among the troops to be worn in their hats, like shamrock on St. Patrick’s Day.

Contrary to the claim of John F.Kennedy in his June 1963 speech to the Oireachtas Thomas Francis Meagher did not lead his troops into the battle of Fredericksburg – he was wounded at the time and sent the Irish brigade into a battle where many of its members were slaughtered.

Almost half of its members were killed or wounded. The famous 69^th New York regiment – the ‘Fighting 69^th’ – lost three quarters of its men. In the confusion and carnage of the battle the Brigade lost one of its distinctive green flags. Some time after Fredericksburg an exhausted Confederate soldier. Michael Sullivan, made his way to Union lines and demanded to be taken to Meagher. When he was brought to the Irish general he reached into his tunic and handed him the flag. He had seen the flag bearer fall and had crawled out, under fire, to recover it.

After the Civil War, Meagher was rewarded by the administration –  if reward it was – with the secretaryship of the territory of Montana. On his arrival the then governor upped and left and Meagher found himself in charge of a large and relatively lawless region of the American west in which the assertive Lakota nation disputed the writ of the Federal government in suitably muscular fashion. Meagher found himself in the middle of some vicious factional disputes among the small white population and it may have been political opponents who were responsible for his mysterious death on 1 July 1867. He died at Fort Benton on the Missouri river when he disappeared from a steamboat. His body was never found. It was presumed to have been whisked away rapidly by the fierce river currents. Various theories have been advanced as to the cause of his death, the most popular is that he was drunk and fell overboard. Others suggest he was killed by native Americans, renegade Confederates or Montanan political enemies. We shall never know.

He was survived by his American wife  Elizabeth Townsend and an Irish son by his Tasmanian wife Katherine Bennett, a son he never met. Statues honour him in the Mall in Waterford and outside the Capitol building in Helena, Montana.

Thomas Francis Meagher was born 190 years ago, on this day.