Wolfgang gave various quotes without citing where they came from. Because I'm anal like that, I'm reposting them here with citations. ;-)
"Roddy McCorley was a Presbyterian from Duneane. He took part in the Battle of Antrim and went into hiding after it. After a year in hiding he was betrayed, tried in Ballymena and hanged in Toome on Good Friday 1799. There is another song on the same subject, written by Ethna Carbery in the 1890s. This song is an older ballad, probably composed in or soon after 1799." * http://www.iol.ie/~terrym/1798.htm#track12 - What seem to be official liner notes for "The Croppy's Complaint - Music & Songs of 1798 / Craft Recordings - CRCD03"
"Ethna Carbery was the penname of Anna MacManus, née Johnston, who was born in Ballymena, County Antrim in 1866. She and Alice Milligan founded the paper called The Northern Patriot and afterwards another called The Shan Van Vocht. She was married to the Donegal writer and folkorist, Séumas MacManus, and died in 1902." * http://www.scotsindependent.org/features/singasang/rody_maccorley.htm and http://www.iol.ie/~fagann/1798/songs7.htm (both used as bios for the author, presumably copied from each other); the scotsindependent one has a link to a MIDI file. Someone really should go and turn that into a tune recording on the DT...)
""After the defeat of the United Irishmen many were unable to return to their former lives and instead became brigands. The most notorious gang in Antrim was led by a man named Thomas Archer. Initially Archer's gang were popular outlaws, exacting revenge on loyalists in the district but, as time passed, their actions became less political and more criminal. During early 1800 the members of the gang were systematically brought to justice and executed. Roddy McCorley was hanged at Toome on 28 February." * http://www.deochandorais.de/misc/98songs.htm (This bit seems to be written by the website author; but e provides a link to sources used, which we might find of interest...)