Administration Letters, 1787-1940 (Series 168)
African American Advisory Board Records, 1998-2009 (Series 402)
Agents and Principals Register, 1894-1905 (Series 128)
Airport
Agreements -- Acquisition & Contract, 1942-1978 (Series 276)
Scrapbooks, 1944-1984 (bulk 1950-1966) (Series 248)
Construction Files, 1937-1946 (Series 84)
Subject Files, Commissioner of Public Works, 1944-1977 (Series 270)
Almshouse Records, 1854-1917 (Series 179)
Appointment Records (County Elections), 1907-1922, 1935-1981 (Series 152)
Appointment Records (Municipal Elections), 1898-1978 (gaps) (Series 153)
Appointments to Office (Govenor's) , 1795, 1800-1840 (Series 112)
Architects Register, 1919-1951 (Series 4)
Assumed Business Names Index, 1900-1933 (Series 46)
1867 Atlas of Westchester County
1881 Atlas of Westchester County
1901 Atlas of Westchester County
1910-1911 Atlas of Westchester County
1930 Atlas of Westchester County
Sanborn Maps and Atlases Collection, 1887-1939 (gaps) (Series 316)
Westchester County Atlases Collection, 1867-1984 (gaps) (Series 315)