William Tilghman earned an Artium Baccalaureus and a Master of Arts from the College of Philadelphia, where he also read law. He began his legal career in Talbot County, Maryland, before serving in the Maryland House of Delegates and the Maryland Senate. Tilghman then practiced law in Philadelphia, Pennsylvania, where he was eventually nominated to the United States Circuit Court for the Third Circuit. After the court's abolition, he returned to private practice and held various judicial positions in Pennsylvania, culminating in his role as Chief Justice of the Supreme Court of Pennsylvania.

William Tilghman's career reveals a deeply rooted commitment to legal and intellectual pursuits, with a notable dedication to the judiciary. His appointments and memberships in prestigious societies suggest a blend of scholarly rigor and judicial authority. Tilghman's ability to navigate and lead within these circles hints at a strategic, perhaps calculated approach to his roles. His positions often intersect with significant historical moments, indicating a potential for unexpected alliances or policy decisions.