Harry C. Trexler was part of a small group of five founding directors of the Pennsylvania Power and Light Company, later renamed PP&L and now PPL Corporation, in Allentown. At the time of its founding, electric utilities were entering a consolidation phase. In 1920, Pennsylvania Power and Light was formed as a holding company including eight smaller utilities. "Trexler also got involved early in the building of utility infrastructure of the Lehigh Valley," author Bill Beck wrote in his biography on PPL.Bill Beck, PP&L 75 Years of Powering the Future: An Illustrated History of Pennsylvania Power & Light Co. (Eden Prairie, MN: Viking Press, 1995), 92, 96, 123, 125, 174, 176, 177, 178, 179, 180. One of Trexler's ventures was the Lehigh Valley Traction Company, a trolley company that generated more electricity than it used. In 1920, Trexler started Lehigh Light & Power, which was merged into PP&L upon its founding. By 1928, Trexler's stature and influence at PP&L allowed him to assume the lead role in selecting John Wise as the company's second president.Beck, 178, 179.
