Maryland, West Virginia & Virginia : Civil War Telegram Map, 1862 (Raster Image)

This layer is a georeferenced raster image of the historic paper map: War telegram marking map. It was published by L. Prang & Co. in 1862. Scale [ca. 1:490,000]. Covers portions of Maryland, West Virginia, the District of Columbia, and eastern Virginia. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator projection (WGS 1984 UTM Zone 18N). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, selected points of military interest, and more. Relief shown by hachures. Includes text: "Explanations.The extraordinary large scale on which this map is drawn has been adopted to make it just what we designed it to be, namely 1st. The most distinct map ever published of the whole Virginia territory, where the decisive battles for the Union will be fought. 2nd. A marking map, that is a map to mark the change of positions of the Union forces in red pencil and the rebel forces in blue, on the receipt of every telegram from the seat of war..." This layer is part of a selection of digitally scanned and georeferenced historic maps of the Civil War from the Harvard Map Collection. Many items from this selection are from a collection of maps deposited by the Military Order of the Loyal Legion of the United States Commandery of the State of Massachusetts (MOLLUS) in the Harvard Map Collection in 1938. These maps typically portray both natural and manmade features, in particular showing places of military importance. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

Historic paper maps can provide an excellent view of the changes that have occurred in the cultural and physical landscape. The wide range of information provided on these maps make them useful in the study of historic geography, and urban and rural land use change. As this map has been georeferenced, it can be used in a GIS as a source or background layer in conjunction with other GIS data.

source map publication date.

map.

None.

The georeferenced raster is a faithfully reproduced digital image of the original source map. Some differences may be detected between the source graphic used and the raster image due to the RGB values assigned that particular color. The intent is to recreate those colors as near as possible. Data completeness for raster digital image files reflect content of the source graphic. Features may have been eliminated or generalized on the source graphic due to scale and legibility constraints The horizontal positional accuracy of a raster image is approximately the same as the accuracy of the published source map. The lack of a greater accuracy is largely the result of the inaccuracies with the original measurements and possible distortions in the original paper map document. There may also be errors introduced during the digitizing and georeferencing process. In most cases, errors in the raster image are small compared with sources of error in the original map graphic. The RMS error for this map is 4348.45101 meters. This value describes how consistent the transformation is between the different control points (links). The RMS error is only an assessment of the accuracy of the transformation.

ESRI ArcGIS 9.1.

Not applicable.