Editing Fort Mifflin (section)

== Later Military Use ==

Fort Mifflin was rebuilt after the Revolution and continued to serve as a military installation for over 150 years. The current stone fortification, designed by French military engineer Pierre Charles L'Enfant (later famous for planning Washington, D.C.), was constructed between 1798 and 1803 as part of a national system of coastal defenses. The fort saw no combat during the War of 1812 but was expanded and modernized in subsequent decades. During the Civil War, Fort Mifflin served as a prison for Confederate soldiers and political prisoners, with conditions that drew criticism even from contemporaries accustomed to the harsh realities of wartime detention.<ref name="cox">{{cite book |last=Cox |first=William V. |title=Fort Mifflin: A Delaware River Fortress |year=1982 |publisher=Diane Publishing |location=Darby, PA}}</ref>

The fort remained an active military installation through both World Wars, serving various support and training functions for the Army and later the Navy. The end of military use came gradually, with the fort decommissioned in 1954 and transferred to the city of Philadelphia in 1962. The National Historic Landmark designation in 1970 recognized both the fort's Revolutionary War significance and the architectural importance of the early republic fortifications that survived later modifications. Today, Fort Mifflin encompasses approximately 49 acres and includes original structures from multiple periods of the fort's history, providing visitors with an unusually complete picture of American military architecture over two centuries.<ref name="nps">{{cite web |url=https://www.nps.gov/places/fort-mifflin.htm |title=Fort Mifflin |publisher=National Park Service |access-date=December 29, 2025}}</ref>