Prior to the war Peirs worked as a solicitor at Ellis Peirs & Co., a firm co-founded by his father. And although he lamented in a December 1918 letter, “My chief trouble is that I have forgotten the little law I ever knew,” Jack did return to the firm after being demobilized. The Law Society Gazette announced, in their September 1919 issue, that he had been made partner, a position he would retain for the rest of his life. There are several issues of the Gazette in the Peirs papers, all containing a mention of him in his military career. The Gazette kept track of Law Society members serving in the military and reported on deployments, honors, and casualties. In March 2017, Meghan O’Donnell wrote an analysis in which she noted how news from the war permeated the professional organization’s publication.