In December 1747, the Assembly made no provision for the defense of the City (Philadelphia) or Providence and many of the inhabitants became alarmed and voluntarily entered into an association for defense. Companies were formed and officers were chosen under the commission by the Provincial Council. Anthony Palmer, President of the Assembly on May 17, 1748 wrote: The Province which very lately was in a defenseless state, is now, through the zeal and activity of the some, who have the love of their country sincerely at heart, rendered capable, with the blessing of God, of defending itself against the designs of our enemies…Arms have been provided, and everyone appears assiduous in qualifying himself for the defense of his country… At considerable expense, erected batteries on the River, so situated and of such strength and weight of metal, as to render it very dangerous for an enemy to attempt the bringing any ships before the city… We think they justly deserve the assistance and encouragement of your House”.
“Officers of the Associated Regiment of the West End of Lancaster County, Over the River Susquehanna.” Dated 1747-1748. Ensign Joseph Irwin (Irvine) is listed under Colonel Benjamin Chambers, Lieut. Colonel Robert Dunning, Major William Maxwell, Captain James Silver, Lieut. Tobias Hendricks command.
Officers of the Provincial Service – 1755. In the fall of 1755, after General Braddock’s defeat, there were several companies of militia sent into Northampton, and other frontier counties, to guard the inhabitants. On August 7, 1755, a number of the inhabitants of Cumberland County heartily joined as a company under the command of Captain Joseph Armstrong. Abram Irwin, Christopher Irwin and John Irwin were listed as privates under Captain Armstrong company.
Robert Irwin was the Waggon Master enlisted on April 12, 1756 under the command of Lieut. Colonel William Clapham of the Third Battalion. Third Battalion known as Augusta Regiment in 1756 gathered at John Harris’ now Harrisburg where the battalion had intended to march against the Indians at Shamokin, under the command of Governor Robert Hunter Morris. They crossed the Susquehanna and marched on the west side and until they came opposite of the town of Sunbury where they crossed over in Batteaux. They built the Fort Shamokin and remained there in garrison until 1758.
The Pennsylvania Regiment, Third Battalion under William Denny, Esq. Lieutenant Governor of the Providence of Pennsylvania and Colonel in Chief list Robert Irwin as Wagon-master.
In 1756, Captain Moses Irwin is listed in Associated Companies of Lancaster County, Pennsylvania.
John Irwin, age 34, born in Ireland enlisted as private May 25, 1759 under Captain Robert Curry of the Pennsylvania Regiment.