[citation needed] In 1750, a two year long complaint lodged by the Six Nations met its culmination, white settlers were illegally trespassing on Six Nations land and erecting homes, fences and other structures, the government sent Richard Peters of Philadelphia and Conrad Weiser and an Indian interpreter to consult with magistrates at Carlisle and have the trespassers removed.
Threatened by this development and the continued activity of British traders in the Ohio Valley, the French redoubled their diplomatic efforts, however in 1750, when Weiser traveled again to Onondaga, he found that the political dynamics in the Six Nations had shifted.
“The said trespassers had likewise given bonds in the sum of five hundred penalty to remove immediately with all their servants, cattle and effects, and had delivered possession of their homes to Mr. George Stevenson for the proprietor's use, and that Mr. Stevenson had ordered some of the meanest of the cabins set on fire.” In December 1750, after being forcefully relocated to the Conococheague settlement, Girtee and Samuel Sanders (or Saunders) in what historical accounts refer to as a "drunken braw" fought which ended with Girtee's death.
In 1756, Girty, his mother and step-father, and his brothers Thomas, George and James were taken captive by a Shawnee war band after an attack on Fort Granville.
Girty was fluent in the Algonquian language dialects, but due to his full immersion and upbringing in the native tribal culture, he was unable to read and write in English upon his return.
[10] Shortly before departing back to Pennsylvania, in the presence of Major William Crawford, Girty attempted to receive compensation from Colonel Lewis for delivering the letter on behalf of Lord Dunmore.
Crawford rejected the proposal,[11] and shortly thereafter Girty deserted his post at Fort Pitt, perhaps in part due to growing hostilities between the Colonials and the Tories.
[13] Simon, James, and George Girty, along with Alexander McKee and Matthew Elliot, were now considered outlaws and traitors to the United States.
Pennsylvania placed a $800 bounty on Simon Girty's head for inciting murder against fellow Americans, and acting as an agent for the British.
[14] From February 22, 1779 to March 1779, Girty accompanied British Captain Bird and warriors of the Wyandot, Mingo, Munsee, and Delaware in the siege to Fort Laurens.
[15] On October 1, 1779, Girty and McKee, leading a large band of Indian warriors, ambushed a peaceful convoy of provisions which had been procured by American states from the Spanish in New Orleans.
However, upon a full inspection of the Wingenim tribal village, Knight recalled seeing four prisoners scalped and dead laying on the ground.
Knight recalled the identity of one killed prisoner, Lieutenant John McKinley, a former officer in the 13th Virginia Regiment, whose head had been cut off and kicked around by the warriors.
Girty then was observed by Knight to order the warriors to shoot Crawford with only powder shots, which caused the flesh to burn.
Daniel Barr's 1998 scholarly paper states that Hugh Henry Breckinridge, a frontier author, made "subtle alterations" to eyewitness statements which had the effect of presenting both the Indians and Girty in particular "in a profoundly negative manner.
[20] On August 19, 1782, Girty, under the command of William Caldwell, along with about 300 Shawnee natives and British Canadians, attacked Bryan Station.
[23][24] After the end of the war, Simon Girty settled in Upper Canada (now Ontario) along with other Loyalists and Indian allies of the British, such as nations of the Iroquois Confederacy.