54325 Main Road

PO Box 1

Southold, NY 11971








Prince Building:

54325 Main Rd., Southold NY 11971

Museum Complex:

55200 Main Rd., Southold NY 11971

Nautical Museum at Horton Point Lighthouse:
3575 Lighthouse Rd., Southold NY 11971

Prince Building Hours:

Society Office: Monday—Friday 10am-2pm
Gift Shop: Monday—Friday 10am-2pm

Archives: By Appointment


Treasure Exchange: 

April 1st through Mid-December    

Tues., Thurs., Fri., Sat., 10am–4pm

Wednesday 1-4pm


January through March             

Saturdays only, 11 am–3 pm

©2019 Southold Historical Society

"Ever Eastward" Exhibit Opens on July 24th!

** Exhibit Extended through October 10th, 2010!!


JUNE 23, 2010

Exhibition on the Cosden Estate to Open in July!

SOUTHOLD, NY. The Southold Historical Society will open a new exhibition in late July documenting the history of the Cosden Estate, one of the largest estate properties that existed on the North Fork. The exhibit will open to the public, Saturday, July 24, 2010 and be open through October 10, 2010. It will be on display in the Mayne Memorial Gallery, located in the Ann Currie-Bell House on the corner of Main Road and Maple Lane, in Southold, NY. The exhibition will be open Saturday, Sunday, and Wednesday, from 1-4pm.

The exhibition, entitled “Ever Eastward: Alfred H. Cosden and his Estate at Southold,” details the life of Cosden and the creation of his Long Island estate named “Eastward.” The 40+ acre estate was located along Soundview Avenue just north of Southold hamlet.

Alfred Cosden was, in addition to being a successful businessman, a famous horse breeder and racer and his stable won many important competitions, including the Belmont Stakes in 1928. That year his racer “Vito,” beat out other horses to claim the top prize on Long Island. Between 1905 and 1935 Cosden owned dozens of horses and won an equal amount of competitions and prizes up and down the East Coast.

“There has been intense interest in the Cosden estate for years,” stated Geoffrey K. Fleming, the Society’s Director. “Because only portions of the estate remain today, it has become part of local lore and new residents are always interested in how it came to be built here,” he continued.

Alfred H. Cosden was a wealthy pharmaceutical executive, originally from Delaware. He and fellow friends Edward Cahoon and Joseph Marshall built large estates here in Southold, but none was more elaborate than the Cosden Estate.

The architect hired to design the estate was James L. Burley, a well respected New York City architect, and designer of Cahoon’s nearby mansion, “Over-the-Sound-Villa.” In 1916 the large house and estate were completed and that summer the Cosden family moved into their new home. Unlike many such houses, this one was not a vacation house. It was to be the year-round residence of the family.

The Cosden estate was large by any standard. It was composed of more than forty acres of woodlands, pasture, and gardens. The house sat opposite a specially designed golf course that was established by Cosden. The mansion lot was four acres, overlooking the bluffs and Long Island Sound and from the house there was an elaborate ninety-eight step staircase down to the private beach below. The grounds were designed to be comfortable and to encourage visitors to stroll and examine the magnificent variety of trees, shrubs, and flowering plants.

Across from the main house on Mount Beulah Avenue were a number of the service buildings. First, there was the complex that contained the stable, garage, pump house, and barn, which was designed to house horses, to provide an area for milking the cows, and to provide a place to protect the family’s vehicles. Behind this complex was the large tractor shed that stored the equipment used to maintain the grounds.

South of the complex were two houses, the Superintendent’s Residence and the Gardener’s Cottage. A pair of lovely Georgian Revival brick structures, the northerly one served as the residence of William V. Cosden, Alfred’s brother and superintendent of his estate. In the southerly located one, the gardener and other servants were housed.

The estate itself was sold and the mansion demolished in 1940. Today several of the outbuildings survive as private homes while the surviving ornate iron fences and gate posts mark portions of the once grand estate.

The exhibition will include a number of period photographs of the mansion and grounds, as well as period black & white films taken on the estate during the years 1927 – 1930. “The films are extremely special to us here at the Society as they show the family enjoying the estate in a manner that cannot be conveyed simply through the use of still photography,” stated Fleming. Other items included in the exhibition will be trophies from Cosden’s racing career as well as a portrait of “Druien,” one of his early horses.

In addition to the objects in the exhibition, the Society has published a new hardcover, illustrated book detailing the history of the estate which will be available for purchase. It contains over seventy period images of the Cosden family, the mansion, grounds, and activities the family enjoyed while living in Southold. The book was researched and authored by the Society’s Director, Geoffrey K. Fleming.

For further information on this exhibition (and images), please contact the Southold Historical Society at (631) 765-5500 or online at www.southoldhistoricalsociety.org.

#PressRelease #2010PressRelease