July 12 in Stewartstown the Catholics defend their church, leaving 22 Orangemen "a-bleeding on the ground." O'Sullivan is jailed, tried, convicted, "and sentenced for to end his life upon a gallows tree." He refuses freedom and reward to turn informer.
July 12 is the Gregorian Calendar (adopted in England in 1752) date for celebrating the victory of William III of Orange in the Battle of the Boyne, July 1, 1690.
The complete title of Zimmermann's broadside is "The Lamentation of James O'Sullivan, Who was executed at Omagh Jail for being concerned in the battle which took place between the Catholics and Orangemen at Stewartstown on the 12th July."
Zimmermann: "This ballad ... [was] perhaps also inspired by the 'party fights' in July 1829. Upwards of twenty men were said to have been killed in County Tyrone.... There was more fighting near Stewartstown in July 1831." - BS
And it would continue for many more years; after the fight at Dolly Brae in 1849 (for which see "Dolly's Brae (I)" and "Dolly's Brae (II)"), the British would pass the Party Processions Act in 1850 to control these fights. But still they march at Portadown.
Stewartstown is roughly on the boundary between the majority-Catholic and the majority-Protestant parts of Ulster; so it's easy to see how life could be very tense there. - RBW