Pierre Gibault Father Pierre Gibault was a Jesuit missionary and priest in the Northwest Territory in the 18th century , and an American Patriot during the American Revolution . Frontier Missionary . Gibault was born 7 April 1737 at Montreal , the son of Pierre Gibault and Marie Saint - Jean , and was baptised the same day . He was educated as a missionary and ordained as priest at Quebec on 19 March 1768 , and was quickly appointed Vicar General of the Archbishop of Quebec for the Illinois country . When France lost the Northwest Territory to Great Britain in 1763 , Jesuit priests were expelled . Catholic communities had to rely on local laity to lead their congregations . Fr . Gibault arrived in Kaskaskia on 8 September 1768 , where he served Catholics of French and Indian ethnicity , as well as members of the 18th Royal Irish Regiment who were stationed there . He first arrived in Vincennes in 1769 , where a crowd greeted him with cries of " Save us , Father ; we are nearly in Hell ! " Father Gibault oversaw a circuit of parishes , including Vincennes , Kaskaskia , Ste Genevieve , and Cahokia . He also visited settlements as far as Ouiatenon , Peoria , and St . Joseph . The territory was still considered dangerous frontier , and Gibault carried a gun and two pistols . The Patriot Priest . Father Gibault was in Kaskaskia in 1778 when George Rogers Clark arrived . According to Clark , Fr . Gibault stated that he supported the Americans , but was concerned for his Catholic congregation . Clark assured him that by the laws of Virginia , they would be free to worship as they wished . Clark also informed Gibault of the newly signed treaty between the United States and France . Gibault convinced the Canadian residents under his care to support the Americans . He further convinced the residents to recognize American continental paper money . Gibault often exchanged Spanish milled dollars for an equal amount of continental promissary notes , and by 1783 estimated that this cost him 7 , 800 livres . Father Gibault , together with Spanish trader Francis Vigo , is considered to have funded most of the Illinois campaign . Clark told Fr . Gibault of his plans to take Vincennes , but Gibault stated that he could do this without troops . Fr . Gibault and Dr . Jean - Baptiste Laffont left Kaskaskia in 14 July 1778 and converted an overwhelming majority of Vincennes residents to the American cause . The population raised a new American flag at the abandoned Fort Sackville , wrapping the British flag around a stone and discarding it into the Wabash River . Gibault returned to Kaskaskia and reported the news to Clark . When Lt - Governor Henry Hamilton retook Fort Sackville and Captain Leonard Helm , Gibault found himself confined to Vincennes . Hamilton then captured Francis Vigo , a Spanish citizen and therefore a non - combatant . Father Gibault conducted Sunday mass , then led his entire congregation to Fort Sackville , where he informed Hamilton that all supplies would be denied to the garrison until Vigo was released . Vigo was released , and informed Clark of the capture of Vincennes . Gibault soon returned to Kaskaskia , and blessed a force of Canadians and Virginians led by Clark to re - capture Vincennes in February 1779 . For his services to the Americans , Gibault was viewed disfavorably by his fellow clergy , who had remained loyal to the British government . Father Gibault actually requested a move to Quebec in 1788 , but was denied by the Bishop due to a disadvantageous opinion that the government had formed of him . In a letter from Cahokia dated 1 May 1790 , Father Gibault detailed his services and the debts owed him to Arthur St . Clair . He asked , as a " concession , " that the United States would legally grant some land in Kaskaskia - which had traditionally been used by priests - to him and his successors . The request was forwarded on and granted by President George Washington , but the newly appointed American Bishop objected . Without land or compensation , Father Gibault moved to New Madrid and became a Spanish citizen in 1793 , pastoring the parish of Saint - Isidore until his death on 16 August 1802 . His body was sent to Canada , but his grave is unmarked .