Federal Township Plats - 1840

<p>This dataset is a derivative of the Federal Township Plats
for Lake County, Illinois, the originals of which were captured on a
high-resolution scanner by the Illinois State Archives. The Lake County
GIS/Mapping division received permission to acquire and georeference these
images using ERDAS Imagine. Since the source material was distorted in an
unsystematic way due to the rigors of time and points of reference were
abundant, the rubber sheeting model in Imagine with the linear option was
chosen to rectify the images. The USGS delineations of the section corners for
their 1:24,000 scale 7.5 minute quadrangles were chosen as a base because they
are a publicly available resource that exists for the entire state of Illinois
should any other counties or organizations wish to make a similar product. This
final product consists of a mosaic of the townships in Lake County also created
in Imagine using their mosaic tool with each township being cropped to its
border in the process.</p>