[2] Covering more than 235 acres (95 ha) along the banks of the Brandywine Creek, the museum and grounds include the first du Pont family home and garden in the United States, the powder yards, and a 19th-century machine shop.

[3] On the hillside below the mansion lies a Renaissance Revival garden, with terraces and statuary,[4] created in the 1920s by Louise Evelina du Pont Crowninshield (1877–1958).

[5] In 1802, French immigrant Éleuthère Irénée du Pont founded black powder mills on the banks of Brandywine Creek[6] after purchasing the property in 1801 for $6,700.

[7] He chose the location for the river's tumble over the Fall Line which provided power, timber and willow trees (used to produce quality charcoal required for superior black powder), the proximity to the Delaware River (on which other ingredients of the powder – sulfur and saltpeter – could be shipped); and the quarries of gneiss that would provide construction materials for the mills.

Hagley Hall was the seat of Thomson's patron the Baron Lyttelton, and the poem's description of a sylvan dale is strikingly reminiscent of the Brandywine Valley.

[12] There are indoor and outdoor exhibitions, along with restored mills, a workers community, and the original home of the du Pont family with an attached garden.

[13] The Museum also explores personal stories of the 19th-century DuPont Company employees, how they lived, and how their lifestyles changed along with new machinery and new production methods.

[15] Hagley's library houses a major research collection of manuscripts, archives, photographs, pamphlets, and books documenting the history of American business and technology.