| The U.S. Coast Survey created highly detailed topographic maps beginning
in 1834. These maps eventually became known as topographic sheets or "T-sheets."
This is a collection of 1,887 topographic sheets dating from 1834 to 1911,
courtesy of the NOAA Central Library
in Silver Spring, Maryland. The sheets have been grouped by state and
then ordered geographically along the coast. The digital files were created
by scanning photographic negatives the original sheets and then inverting
the images to a positive format. The negatives are gross reductions in
size from the map originals. The collection was scanned at a resolution
of 1200dpi. The variance in the quality of the images in this collection
is a function of the condition of the photographic negatives from which
they were derived. |
