When Harold Detweiler and his older brother Willis co-founded the business in 1946 the firm was known as Detweiler Brothers. Harold had recently completed a three year stint as a milk tester, traveling throughout Montgomery County and parts of Bucks and Berks Counties visiting the many family farms that still existed in those days. World War II had just ended and Harold saw his future as an accountant. He enrolled in Lansdale School of Business to acquire the needed education while attending to the demands of a young family and a new company.

Within a few years Willis, who suffered a handicap (a disfigured spine), left the firm and moved to Lancaster County where he took a leadership position with Mennonite Central Committee, a relief agency of the Mennonite church. After he had served more than 20 years with MCC, Willis chose to return to his accounting roots and opened a non-certified practice in Akron, Pennsylvania where he lived. By the early 70’s he realized his practice couldn’t compete with firms that had made the decision to be certified so he approached his younger brother with the idea of merging practices and DHA’s presence in Lancaster was born. This office remained a part of the firm until January 1, 2007 when the move was made to formally dissolve the partnership while maintaining an affiliation with the new practice and its partners.

Over the years, Harold also acquired other practices, including a small bookkeeping franchise in Norristown and sole proprietor firms in Pennsburg and Warminster. Each acquisition brought with it a new client base and sometimes the expertise of the owner, if they chose to stay with the new firm.