The Middletown South Green Historic District was listed on the National Register of Historic Places in 1975. Portions of the content on this web page were adapted from a copy of the original nomination document. 
The Middletown South Green Historic District encompasses approximately three blocks bordering on and near horsehoe-shaped Union Park. Located immediately southeast of the central business district, it is aligned on an approximate north-south axis. Thirty-one buildings are included in the boundaries of the Middletown South Green Historic District and are primarily residential, although there are two churches, two parish houses, a synagogue, two funeral homes, the lodges of two fraternal orders and several old homes now used for professional offices. With the exception of a few eighteenth and twentieth century structures, the Middletown South Green Historic District is representative of 19th century styles typically found in a mid-sized industrial and commercial town.
Union Park, around which the Middletown South Green Historic District is located, is a large, grassy open space with sparsely scattered trees. A large part of the district surrounds Union Park on two sides creating two distinctive streetscapes which join at the south end of the Park and continues south along South Main Street. Compatible historical streetscapes are also located on Crescent Street, which parallels Pleasant Street.
The east boundary of the Middletown South Green Historic District follows the east side of Crescent Street where the Middlesex Memorial Hospital is located. The hospital complex forms a definite visual barrier to the continuity of the district. An area of fairly modern and much altered older buildings forms the south boundary immediately south of #4 Crescent and #61 South Main Street. The back lot lines of the houses on South Main Street form part of the western boundary, separating the district from a residential area. This boundary crosses Church Street to include the buildings to the west. The South Green between Broad and Main Streets further west are buildings of residential and commercial use which are a part of the central business district and of a very different character. The northern boundary then follows Main Street and Main Street Extension, separating the Middletown South Green Historic District from a group of structures which are either more modern buildings or much altered old ones, also of a mixed residential and commercial nature.
Throughout the Middletown South Green Historic District there are structures of varying visual and architectural quality. A few examples of contributory buildings are 27 South Main Street, 29 and 51 Crescent Street, and 27 Pleasant Street.
The Middletown South Green and surrounding streetscapes are listed to the National Register of Historic Places because: 1) The area is a significant visual focal point which clearly defines the south end of Middletown's commercial business district, 2) The area contains a large number of relatively unaltered structures that represent high styles of architecture that were popular at the time Middletown emerged into a regional trade and manufacturing center, 3) Taken together, the buildings, the South Green and their relative setting survive in a sate of nearly complete historical integrity that maintains the scale and character that was created as the area was originally developed. The orientation of large scale structures around a definite open space provides a distinctive visual unit that is unique in the City of Middletown.
The buildings surrounding the green serve a wide variety of purposes which attract many townspeople for business or religious purposes, but also many come just to enjoy the square as a lovely open space. Most important, however, are the architectural styles to be found along the green, for they span a period of 250 years, and, so, are of historical significance to Middletown.
Two eighteenth century buildings are among the oldest surviving structures in the town. Compared to the nineteenth century residences, which are much larger and much more ornate, they reflect by contrast an increased affluence and an evolution in architectural taste. The design of the nineteenth century churches portray stylistic preferences, but they also provide insight into the social priorities of the times.
Of particular interest is the Mather-Douglas-Santangelo House which commands the most imposing site along the green. The house was built between 1811 and 1813 by Thomas Mather, a wealthy Middletown businessman. In the late 1850's Benjamin Douglas bought the house which was then being leased to the Middletown Female Seminary. Douglas made his fortune by inventing and producing a revolving standing pump. A prominent abolitionist, he was also involved in Connecticut politics, first as Mayor of Middletown from 1850 to 1856, then as lieutenant governor of the state in 1861-1862. As a member of the electoral college in 1860, he cast his vote for Lincoln.
Leo B. Santangelo, Mayor of Middletown, from 1934 to 1936 also lived in this house while in office.
Today  the Mather-Douglas-Santangelo House serves as the meeting place for the Fraternal Order of Eagles. Other buildings along Union Square are used for a wide variety of purposes, for there are churches, a synagogue, a funeral home, several residences and a YMCA.
However, the South Green is not only of architectural interest for it is a valuable open space in the fabric of the community. In the early nineteenth century, the area was prime residential land, for the slope up which terminates at the Mather House afforded each building view of the Connecticut River below. Since it was close to the business section of the town as well, the South Green area became a very prestigious area. Though the view of the river is now obstructed, the open space still gives an expansive residential character to this part of Middletown, which is enjoyed by many residents going to churches, temples, clubs or just walking to the downtown shopping area. Thus, Middletown's South Green not only reflects architectural and town history, but it attracts the townspeople to observe and enjoy their heritage.
Beers, J.H. and Co., Commemorative Biographical Record of Middlesex County, Connecticut, Chicago, 1903.
Beers, Jas. B. and Co., History of Middlesex County, Connecticut, J.B. Beers and Co., New York, 1884.
Brainerd, A., Middletown Illustrated, Westchester, Connecticut, 1877.
Douglas, C.H.J., A Collection of Family Records, E.L. Freeman and Co., Providence, Rhode Island, 1879.
Field, D.D., Centennial Address, Wm. B. Casey, Middletown, 1853.
Mather, Horace E., Lineage of Reverend Richard Mather, Press of the Case, Lockwood and Brainard Co., Hartford, Conn., 1890.
Mather, John, Genealogy of the Mather Family, E. Geer, Hartford, Conn., 1848.
Strother, Horatio T., The Underground Railroad in Connecticut, Wesleyan University Press, Middletown, Connecticut, 1969.
Crescent Street • Main Street Extension • Main Street South • Pleasant Street