The Town of Portland is on the shore of Lake Erie west of the City of Dunkirk. The Lakeview Shock Incarceration Correctional Facility is within Portland. Because the residents of this facility are counted as Portland residents by the U.S. Census Bureau, most statistics about the town are heavily skewed and not representative of the non-institutionalized population.
The region was first settled in 1804. The Town of Portland was founded in 1813 from the Town of Chautauqua. Subsequently, the town was reduced in size to form two new towns: Ripley (1816) and Westfield (1829).
A genealogical history of Portland, New York was published in 1873 by Dr. H. C. Taylor titled "Historical Sketches of the Town of Portland, New York". An all names index was created for this book by Agnes Lee Mitchell in 1989 and published by the Chautauqua County Genealogical Society.