I have listed below all the towns (to the best of my knowledge) which have either been abolished or created since 1865.  Some if this information was found in the following publications:

County Formations and Minor Civil Divisors of New York State (Salt Lake City, 1965)

New York Civil List (1855-1863) and its successors Civil List and Forms of Government of the Colony and State of New York  (1864-1879) and Civil List and Constitutional History of New York (1879-1891).

Please note that both contains some errors and the former omits some New York State towns completely.  In any case, here is the listing I have compiled:


Towns abolished since 1865

Town of Castleton       became part of New York City                 1897
Town of Elko    became part of Town of Coldspring       1965
Town of Flatbush        became part of New York City                    1897
Town of Flatlands       became part of New York City                    1897
Town of Flushing        became part of New York City                    1897
Town of Gravesend       became part of New York City                    1897
Town of Greenbush       became city of Rensselaer                       1897
Town of Highmarket   merged into Town of West Turin     1972
Town of Jamaica became part of New York City                    1897
Town of Lansingburgh    became part of City of Troy and Town of    Schaghticoke 1901
Town of Morrisania      became part of New York City                    1897
Town of New Lots        became part of New York City                    1897
Town of New Rochelle  became city of New Rochelle       1899
Town of New Utrecht    became part of New York City     1897
Town of Newtown became part of New York City    1897
Town of Northfield      became part of New York City    1897
Town of Rome    became city of Rome                     1870
Town of Saratoga Springs        became city of Saratoga Springs 1915
Town of Southfield      became part of New York City                    1897
Town of West Chester    became part of New York City    1897
Town of West Farms      became part of New York City    1897
Town of Westfield       became part of New York City    1897
Town of White Plains    became city of White Plains     1916
Town of Wilmurt merged into Town of Ohio                1918




Towns created since 1865

Town of Albion (Orleans)        created from Town of Barre      1875
Town of Altamont        taken from Town of Dickinson (Franklin) 1890
Town of Ashland (Chemung)       created from Towns of Elmira, Southport & Corning       1867
Town of Babylon taken from Town of Huntington   1872
Town of Clare   created from Town of Pierpont                  1890
Town of Clifton created from Town of Pierpont                  1868
Town of Colonie created from Town of Watervliet 1895
Town of Delaware        created from Town of Cochecton  1869
Town of Deposit created from Town of Tompkins   1980
Town of Dickinson (Broome)      created from Town of Binghamton 1890
Town of East Rochester  taken from Towns of Perinton and Pittsford      1981
Town of Elko    created from Town of Salamanca  1890
Town of Forestport      created from Town of Remsen                    1868
Town of Green Island    taken from Town of Watervliet   1895
Town of Highlands       taken from Town of Cornwall                    1879
Town of Inlet   taken from Town of Morehouse    1901
Town of Lyonsdale       created from Town of Greig              1873
Town of Minetto created from Town of Oswego                     1916
Town of Mount Kisco     taken from Towns of Bedford and New Castle      1977
Town of North Harmony   created from Town of Harmony    1919
Town of Piercefield     created from Town of Hopkinton  1900
Town of Red House       created from Town of Salamanca  1868
Town of Santa Clara     taken from Town of Brandon      1888
Town of Stony Point     created from Town of Haverstraw 1865
Town of Tuxedo  taken from Town of Monroe       1889
Town of Ulster  created from Town of Kingston   1879
Town of Wappingers      created from Town of Fishkill   1875
Town of Waverly taken from Town of Dickinson (Franklin) 1880
Town of Woodbury        taken from Town of Monroe       1889

Any additions to this list are welcome.