The 1,500-acre woodland estate of Robert Henry Allerton, art collector and a benefactor of the Art Institute of Chicago, was carved out of the heart of the 12,000-acre agricultural enterprise of his father, Samuel, who owned more than 80,000 acres of Illinois farmland. Allerton built the Georgian-style manor house in 1900. In collaboration with John Gregg, whom he ultimately adopted, he developed the gardens between 1902 and the 1940s as a series of landscaped spaces, including a reflecting pond, a ten-acre meadow, woodland gardens, a 30-acre demonstration prairie, display gardens and multiple formal garden rooms, home for Allerton’s extensive sculpture collection. The natural areas include the floodplains adjoining the Sangamon River. More than 14 miles of trails wind through the landscape. An interest in cultivating the land, both creatively and horticulturally, led to an intense commitment to environmental stewardship. In 1938, Allerton moved to Hawaii and developed extensive gardens in Lawaii-Kai on Kauai, now the National Tropical Botanical Garden. In 1946, Allerton gave the Illinois estate to the University of Illinois at Urbana-Champaign that manages the property as the Allerton Park & Retreat Center. It was designated a National Natural Landmark in 1970 and listed on the National Register of Historic Places in 2007.