In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Agglethorpe like this:
AGGLETHORPE, a joint township with Coverham, in Coverham parish, W. R. Yorkshire. See Coverham.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Agglethorpe has changed, please see our redistricted information for the modern district of Richmondshire. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Agglethorpe and units named after it.
GB Historical GIS / University of Portsmouth, History of Agglethorpe, in Richmondshire and North Riding | Map and description, A Vision of Britain through Time.
Date accessed: 30th July 2014
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Agglethorpe".