Comparative Accuracy in Four Civil War Maps of the Shenandoah Valley: A GIS Analysis*

Abstract

Both simple and three-tiered sinuosity measures are derived for reference points along study map representations of the Shenandoah river system. These data are then statistically compared to corresponding sinuosity data from USGS topographic quadrangles to identify the relative accuracies of the historical maps. This article offers evidence to refute the common historical assumption that Hotchkiss provided Maj. Gen. Thomas ''Stonewall'' Jackson with terrain intelligence that was far superior to that available to his Union opponents. Evidence indicates that maps by Union cartographers as well as the prewar Bö ÿe-Buchholtz map were at least as accurate, or superior to, the work of Hotchkiss.

Using Spatial Analysis and Geovisualization to Reveal Urban Changes: Milan, Italy, 1737–2005

“…Control points are features (e.g., corners of buildings, street intersections) on the ground that are clearly recognizable on both maps. This procedure has become standard in historical cartography studies, dating back at least to Eduard Imhoff 's seminal 1939 work (cited in Ravenhill and Gilg 1974, 48), and in recent decades it has been used, with slight variations, in several studies addressing the accuracy of historical maps at a variety of scales (Andrews 1974;Stone and Gemmell 1977;Murphy 1979;Hsu 1978;Yerci 1989;Strang 1998;Pearson 2001Pearson , 2004Pearson , 2005. For this study, we located approximately 50 CPs for each historical map.…”

Civil War Maps of the Battle of Stones River: History and the Modern Landscape

“…While most researchers have concentrated on measuring planimetric accuracy using point features, others have looked at linear measurements (Hooke and Perry, 1976;Lloyd and Gilmartin, 1987;Locke and Wyckoff, 1993;Pearson, 2005). Lloyd and Gilmartin (1987) examine the accuracy of representation of the coastline of South Carolina in historical maps ranging from 1757 to 1865, shifting, stretching and rotating the historic coastline to match current representations, in a way analogous to what we do using control points in this paper.…”

“…Locke and Wyckoff (1993) compare the location of rivers in the Colorado-Green River system on historical and modern maps and use nearest neighbor analysis to evaluate the accuracy of different maps. Pearson (2005) also looks at rivers, but his methods are from hydrology. He calculates the accuracy of the historical maps by measuring the sinuosity, defined as the ratio between channel distance and straight distance between two points, of the river system as shown in the historical maps and in contemporary representations.…”

Deconstructing Galbraith: A Geostatistical Analysis of Cartographic Intent

“…Nevertheless, this research represents an effort to actually deconstruct a map's structural components in a GIS to provide data with which to infer cartographic decisionmaking in contrast to stated design principles. In this it is unique, as previous cartometric studies have tended to focus on what Harley (1989, p. 8) calls 'the Examples of studies accessing accuracy in historical maps include the following: Giordano and Nolan, 2007;Hooke and Perry, 1976;Hsu, 1978;Hu, 2001;Laxton, 1976;Lloyd and Gilmartin, 1987;Locke and Wyckoff, 1993;Murphy, 1979;Pearson, 2005;Pulsipher, 1987;Ravenhill and Gilg, 1974;Strang, 1998;Wolter, 1972;and Yerci, 1989. Accuracy assessment is a compelling avenue for cartometric investigation because it is frequently informative specifically to historical cartography and generally to other historical disciplines.…”