The story, verified.

01 · Before the famous discovery

In the late 1830s, workers digging fertilizer-rich marl on John Estaugh Hopkins’s property encountered unusual large bones. The bones were not recognized as a nearly complete dinosaur specimen at the time. In 1858, William Parker Foulke investigated the location and directed excavations; anatomist Joseph Leidy studied the recovered fossils and described the animal.

Sources: Rutgers Geology Museum ↗ · National Park Service nomination ↗

02 · What was actually found?

The 1858 find was unusually informative, but not a complete skeleton. The skull was missing; recovered material included limb bones, vertebrae, jaw fragments and teeth. Calling it the “first dinosaur ever found” is misleading: isolated dinosaur fossils were known earlier. The defensible claim is that it was the first relatively complete dinosaur skeleton discovered and later mounted for public display.

Sources: NPS historical documentation ↗ · Linda Hall Library ↗ · Academy of Natural Sciences ↗

03 · The first mounted dinosaur

In 1868, artist and naturalist Benjamin Waterhouse Hawkins assembled a public mount at the Academy of Natural Sciences in Philadelphia, working with Joseph Leidy’s research. The reconstruction incorporated modeled missing parts and reflected nineteenth-century anatomical ideas; it should not be mistaken for a fully preserved fossil skeleton.

The Academy’s modern reconstructed mount returned to Dinosaur Hall in July 2025. Its original fossils remain part of the Academy’s research collections. Update (September 2026): The Academy's public museum closed on September 30, 2026, although scientific collections and research continue. Official closure announcement →

Sources: Academy: Haddy Returns, July 2025 ↗ · Dinosaur Hall ↗

04 · Life in ancient New Jersey

The Academy places Hadrosaurus foulkii at approximately 81–79 million years ago, during the Late Cretaceous. Its coastal environment was different from modern Haddonfield. It was a plant-eating dinosaur in the wider duck-billed dinosaur lineage. A common illustration of a duck-billed dinosaur is not necessarily an accurate portrait of the particular Haddonfield specimen, because its skull was not recovered.

Source: Academy Dinosaur Hall ↗

05 · From state symbol to national landmark

New Jersey designated Hadrosaurus foulkii its state dinosaur in 1991. The discovery site, near the end of Maple Avenue, was designated a National Historic Landmark on October 12, 1994 (federal record 94001648). Some secondary accounts give 1995; we use the official NPS date. The public marker and commemorative park date to a 1984 Eagle Scout project by Christopher Brees, documented by the Smithsonian.

Sources: New Jersey Legislature ↗ · NPS listing ↗ · Smithsonian inventory ↗

06 · The real bronze Haddy

The downtown bronze sculpture was created by John Giannotti and installed in October 2003 at Kings Highway and Lantern Lane. The Haddonfield Outdoor Sculpture Trust describes it as a community project initiated by the Haddonfield Garden Club. Dimensions vary slightly across published descriptions: Roadside America reports 18 feet long and 8 feet tall, while the artist lists 17 feet in length. We do not treat either figure as an independently verified measurement.

Sources: Haddonfield Outdoor Sculpture Trust ↗ · Artist’s studio ↗ · Roadside America ↗

07 · Why Haddonfield matters today

There are two distinct places to visit: the downtown bronze sculpture and the discovery-site memorial at the end of Maple Avenue. The fossil pit itself lies in a ravine beyond the commemorative area; visitors should remain on public paths and respect posted restrictions. The Historical Society also describes a self-guided historic trail.

Sources: NPS site description ↗ · Historical Society trail reference ↗ · I Know Dino visitor account ↗

Editorial standards & unresolved details

• “First dinosaur discovered”: an oversimplification; we say first relatively complete dinosaur skeleton and first publicly mounted dinosaur.
• 1858 versus 1859: the excavation took place in 1858; the Academy dates Leidy’s first formal species description to 1859.
• 1868 versus 1869: the Academy’s detailed history and 2025 release identify the original mount as 1868; one Academy overview uses 1869. We prioritize the detailed exhibition records.
• State fossil versus state dinosaur: New Jersey officially designated the state dinosaur in 1991; casual references to “state fossil” are not the precise title.
• Images: photographs on third-party websites are not automatically reusable. Our archive credits each reused image; photos of the bronze Haddy require a suitable license or permission.