The George Rogers Clark National Historical Park, located in Vincennes, Knox County, Indiana, is of supreme national significance as the site of Fort Sackville, where Colonel George Rogers Clark led a daring and improbable winter expedition to capture the British fort on February 25, 1779. Clark's force of approximately 170 American and French volunteers marched through miles of icy, flooded wilderness from Kaskaskia, Illinois, to launch a surprise attack on the British garrison led by Lieutenant Governor Henry Hamilton. The surrender of Fort Sackville effectively ended British hegemony in the region and secured the vast Old Northwest Territory-encompassing the future states of Ohio, Indiana, Illinois, Michigan, and Wisconsin-for the United States, a territorial acquisition formalized in the 1783 Treaty of Paris which doubled the size of the nascent nation.

Today, the site is dominated by a monumental classical memorial constructed between 1931 and 1933 to commemorate Clark's heroic achievement and the expansion of the United States. Designed by renowned architect Frederic Charles Hirons, the circular Beaux-Arts style memorial stands on the banks of the Wabash River, housing a larger-than-life bronze statue of Clark sculpted by Hermon Atkins MacNeil and a series of magnificent murals by Ezra Winter depicting the campaign. Authorized as a unit of the National Park Service in 1966, the park is not only a tribute to a pivotal Revolutionary War triumph but also a stunning example of early 20th-century commemorative architecture and civic art.

The Vincennes Historic District is of exceptional historical significance as the oldest continuously inhabited European settlement in Indiana and a pivotal political, military, and cultural hub of the early American frontier. Established as a French fur trading post around 1732, Vincennes transitioned through French, British, and American control, serving as a critical theater of operations during the American Revolutionary War. The district's historical prominence was cemented in 1779 when General George Rogers Clark captured Fort Sackville, securing the vast Old Northwest Territory for the United States. Following the war, Vincennes served as the first capital of the Indiana Territory from 1800 to 1813 under Governor William Henry Harrison, making it the administrative cradle of the region where early government, education, and journalism were first established.

Architecturally, the district encompasses a remarkably rich and diverse collection of structures that span nearly two centuries of development along the Wabash River. The physical fabric of the district showcases a transition from rare French Creole vernacular building techniques to formal Federal, Greek Revival, and Victorian styles. Among its most distinguished contributing properties are "Grouseland," the grand Federal-style home of William Henry Harrison the modest two-story frame Indiana Territory Capitol building and the Basilica of St. Francis Xavier (the Old Cathedral), which represents the oldest Catholic parish in Indiana. Together, these well-preserved civic, religious, and residential buildings illustrate the transformation of Vincennes from a remote colonial outpost into a prosperous, highly influential 19th-century American city.