Most of the 145 acres which now constitute the Museum property originally belonged to poet, lawyer, conservationist, political activist, patron of the arts, and preservationist William Cullen Bryant, who settled in Roslyn in 1843. Bryant's home was Cedarmere, across what is now Bryant Avenue, at the edge of Hempstead Harbor. It became an intellectual and cultural center for some of the greatest minds of the mid-to-late-19th century. Bryant, long-time editor of the New York Post, also helped promote the cultural climate in Roslyn by founding the village's public library which still bears his name. In 1862 Bryant had a cottage built on his property for his friend and fellow poet, Miss Jerusha Dewey. That house still stands just off the museum's ring road. In 2011, the Dewey cottage was restored by the Roslyn Landmark Society.
In 1900, Lloyd Stephens Bryce purchased Bryant's Upland Farm and commissioned the architect Ogden Codman, Jr. to design Bryce House on an elevated site overlooking Hempstead Harbor. That house is now Nassau County Museum of Art. Bryce was an attorney whose career included the fields of politics and literature. He was appointed Paymaster General of New York State in 1866 and subsequently was elected to Congress. He also served as Minister to The Netherlands and Luxembourg during the Taft administration, from 1911 to 1913. Bryce is best known as editor and owner of The North American Review, a forum for international opinion on social, political, and cultural affairs. Edith Wharton, who frequently collaborated with Ogden Codman, was a frequent contributor to this journal.
In 1919 Henry Clay Frick, co-founder of US Steel Corporation, purchased Bryce House as a gift for his son, Childs Frick. Childs and Frances Frick hired British architect Sir Charles Carrick Allom to redesign the facade as well as the interior of their new home, which they named Clayton.
Childs Frick graduated from Princeton in 1905 and became a vertebrate paleontologist and devoted naturalist. He was a quiet and reserved man, well-read and always abreast of current affairs. Childs was an avid sportsman who enjoyed swimming, tennis and polo as well as skiing and golf. The estate included two tennis courts (one grass and one clay), a polo field, two ponds, a swimming pool, bridle paths, and a ski slope with its own snow-making machine. In 1936, Frick commissioned the building of Millstone Lab on his property, it was so named for the two colossal millstones placed by the entrance. This structure later housed the Museum's Art Studios. In addition to his work in paleontology, Frick had an active interest in zoology and botany, establishing a monkey house, an aviary and a bear pit along with keeping otters in a pool near the laboratory. His collections were described by fellow scientists as meticulously catalogued, classified and preserved. He was an early member of the Department of Vertebrate Paleontology at the Museum of Natural History in Manhattan. Childs Frick contributed over 250,000 specimens of mammal fossils to the Museum of Natural History and helped to plan and finance its famous Hall of Mammals. The Pinetum, opposite the laboratory, was originally part of an experimental planting of over 400 conifer specimens from all over the world to study how these species would adapt to this particular latitude. About 200 of those survive today.
Childs' wife, Frances Dixon Frick, shared her husband's enthusiasm and interest in botany. She enjoyed working in her greenhouse and retained Marion Cruger Coffin, a fellow of the American Institute of Landscape Architects in 1925 to redesign the formal garden. Coffin was one of the first and foremost female landscape architects in the United States, one of the first women to graduate from a formal program and establish her own practice.
The formal garden was a 450-foot rectangular flower garden divided into four sections by yew hedges. Private contributions and volunteer labor enabled the Museum to restore the teak Milliken-Bevin trellis and maintain the rose and azalea gardens, and a further, more extensive restoration was made possible in 1993 through a generous grant from New York State's Environmental Quality Bond Act. In 2000 Mrs. Peggy N. Gerry, a life-long preservationist and Roslyn resident, made a generous gift to the Museum, in memory of her husband so that the garden could be fully restored according to Marion Coffin's blueprints which are housed in the Museum's archives along with photographs of the garden taken in the 1930s.
Frances and Childs Frick lived at Clayton with their children, Adelaide, Frances, Martha and Clay, for almost 50 years. Childs died in 1965 at the age of 81. Four years later the estate was purchased by Nassau County with the intention of establishing Nassau County Museum of Fine Art administered by the county’s Office of Cultural Development. In 1989, the Museum became a private not-for-profit institution and is now governed and funded by a private board of trustees. A sculpture park was also begun in 1989 and became one of the largest publically-accessible sculpture parks in the Northeast. A major exterior restoration of the historic mansion was undertaken some years ago; the mansion was then renamed the Arnold and Joan Saltzman Fine Arts Building.
The 145 acres surrounding Nassau County of Art is designated as a nature preserve. The land has an ancient history, owing its unique and varied topographical features to the glacier that receded from here more than10,000 years ago. Its use is documented from the earliest owners of record, the Manhasset Indians, through Dutch and English land grants in the 17th century, to Childs Frick's development of the pinetum and Formal Garden.
The eight marked trails on the map were in existence during the Frick’s ownership, some as driveways accessing Bryant Avenue or Motts Cove Road. The property is home to a comprehensive collection of conifers, lush landscaped grounds with many fine specimen trees, steep forested ravines, old fields in various stages of succession, young woodlands, forest borders, and a number of different forest types including Tulip tree, American beech, oak, hickory, and maple. The diverse habitats are also home to a number of birds, including great horned owls and red-tailed hawks.