On the 10th July, the remnants of the great Wexford Unite Irishmen army [an estimated 1600 men], under Ryan as General, with Colonels Perry, Fitzgerald, and Rossiter, and Garret Byrne, with part of the Wicklow rebels, following the battle of Carnew and after a long forced march to County Kildare, halted near Prosperous. On perceiving a body of troops moving after them they took a strong position near the heights above the town, a bog in front, only passable by a narrow road, through which an army should march to attack them. (This is possibly the hill of Ballynafagh). They had taken the precaution to place their bullock’s baggage, etc., in such a situation on the road that their riflemen could fire with precision from behind them.
A heavy column of musketeer and pikemen, in trenched in the ditches, assumed so formidable an appearance, that his majesty's troops drew off without firing a gun, and left them to prosecute their march unmolested (to the Timahoe camp).
Letter date: July 27, 1798 by Felix Rourke