Maps

Maps, map-making, and cartography played crucial roles in the Civil War, and we believe they play similarly important roles in the current study and understanding of the war-time capital. Civil War Washington has created a project geographical information system (GIS), which combines historical maps and historical information with modern technology. The dynamic map interface allows users to examine digitized period maps of the District, to move between current and historical views, and to select one or more feature layers (such as hospitals, theaters, and freedmen's villages) and view information about these locations. Tools for search and analysis are also available. Read more...

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How to use the map

The Civil War Washington mapping application has been designed for a range of users, from the casual browser to the serious researcher. This tutorial introduces users to key functionality of the application. For more information about the historical maps used and how we built the mapping application, see About the Civil War Washington Maps and GIS. If you have questions or comments about the maps or this tutorial, please contact the project team.

Contents

Overview

Overview

Figure 1: Primary features, or widgets, for using the map.

Users will interact primarily with several main components, or widgets, in order to explore available historical data and achieve custom map views. These widgets are highlighted in Figure 1 above.

A navigation feature on the left side of the mapped area allows for zooming and panning about the map, although, like many major mapping applications, users may also choose to use common click-and-drag and double-click methods to pan and zoom, respectively. Users with scroll button mice will be able to scroll to zoom in and out.

A search widget at the bottom left of the mapped area allows users to conduct text searches for desired records in the map.

Because of the historical nature of the default basemap and data, a contemporary inset map application is always available by clicking the arrow in the bottom right of the mapped area. This inset map shows a modern view of the map extent in a small window.

A "basemap switcher" widget at the top right also allows users to choose from among several basemap views (background maps upon which data are drawn), including two historical basemaps, contemporary satellite imagery, and a modern basemap, allowing for quick comparison.

Not all layers are active by default, and some users may not want to see all the default layers on their map. To the left of the basemap switcher widget, a drop-down menu lists all the active layers. These layers can be toggled on or off at any time.

Several additional widgets are available through the menu bar at the top of the window. These include a map legend, time slider, bookmarks feature, a draw and measure widget, a print map function, and a widget that allows users to download the raw GIS files to use with mapping software programs. These widgets are described in detail throughout the following sections.

Add or remove layers

By default, a number of feature layers are active in the map view, while several others are inactive. Currently, there are 17 available layers, any number of which may be toggled on or off at a given time. To change the layers shown on the map, look for the "More..." button at the top of the mapped area, below the menu bar (see Figure 2). Clicking or hovering over the "More..." button will activate a drop-down menu that lists all available map layers. A scroll bar on the right allows the user to navigate through the entire list of available layers. Layers can be displayed or hidden by checking or unchecking the corresponding boxes in the menu. A checked box indicates that a layer is active.

More

Figure 2: The "More..." button allows users to see the full list of mapped features and to toggle layers on and off. [Back to text.]

View the legend

By default, the legend is closed, in order to maximize the view of the mapped area. To open the legend, click on the legend icon in the menu bar at the top of the application window (see Figure 3). When the legend is open, it displays only the active layers. If data layers are added or removed, they will appear and disappear from the legend, respectively.

Legend

Figure 3: Clicking the legend icon will open a window that shows the map legend, which associates icons used on the map with the types of places they represent. [Back to text.]

Change the basemap

The standard historical basemap is Albert Boschke's Topographical Map of the District of Columbia (1861). Users, however, have the option to modify the basemap. Available are lighter and darker versions of the Boschke map, a current basemap, a current satellite view, and a second historical basemap, J. G. Barnard's Map of the Environs of Washington (1871).

The basemap switcher is located at the top of the map window, on the right, below the menu bar (see Figure 4). Here, users may move among the four different basemaps. There are two options to move among the available views. The first option is a slider bar that can be dragged across the four views. As the slider is dragged, the images fade and blend into one another, so it is possible to achieve unique hybrid views by positioning the slider between two different views. Alternatively, clicking the title of a desired basemap view (e.g., "BARNARD MAP") will switch the background map accordingly. Notice that the active map view tab is darkened when that layer is active.

Switcher

Figure 4: The basemap switcher allows users to move among four basemaps and to create hybrid views that blend basemaps. [Back to text.]

Search for features

The search or identify widget launches automatically as a box in the bottom left of the window when the mapping application is opened (see Figure 5).

Search

Figure 5: The search or identify widget, and the search widget menu icons (highlighted in red). The icon on the left allows users to select specific areas of the map within which to search. The middle icon, "select by attribute," allows users to enter search terms and search for features by name. The icon on the right is the "results" tab, which provides a list of features that meet search criteria. In the above image, the white underline indicates that "search by attribute" is the active page. Users can toggle between these widget abilities by clicking on these icons. [Back to text.]

To search for a particular feature or place, simply type the desired name into the text box. The search is not case sensitive, and searching with only partial text will return all records that match the text (e.g., searching for the text "union," without quotation marks, will return "Union Chapel," "Union Bethel Methodist Episcopal," and all other records that contain that text).

The widget will switch automatically to the results tab, regardless of whether or not any records are returned. (The results tab is a small icon in the widget window that resembles a database table; see Figure 5).

If records are returned by the search, they can be clicked, and the map view will zoom to the clicked feature location. The search widget will have to be closed before the feature can be explored further. To close the widget, click the "X" at the top right of the widget window.

If no records match, a prompt will indicate that there were "No features found." Whether or not records were returned, to begin a new search, click on the center icon in the menu bar, "Select by attribute" (resembles binoculars over text). Click once on the "Clear" button to remove any records that may have been selected in the search. Begin a new search by entering text as usual.

The search icon on the far left allows users to select features from a specified area of the map. Clicking on this icon will produce a series of drawing tools, which can then be used to draw circles, rectangles, polygons, lines, etc. The widget will then return all features within the selected geographic area.

The aforementioned search features should be adequate for all basic searches. However, users wishing to conduct a more specific search have the option to further restrict the search to a specific data layer (see Figure 6). These searches by layer are case-sensitive. To specify a layer through which to search, click once on the drop-down menu next to "Search layer" and choose a different layer for the search.

search

Figure 6: Users can restrict their search to a specific layer by selecting that layer from the drop-down menu. Unlike the standard search, these types of specific searches are case-sensitive. [Back to text.]

See more information about a place

All selectable layers that are drawn on top of the basemap contain embedded feature information. This information can be accessed at any time by clicking on the feature in the map. When a feature is selected in this way, a context box will appear next to the feature indicating basic information about that place (see Figure 7). Clicking elsewhere on the map will deactivate the information box.

Depending on the feature type and available historical records, the amount of information will vary (for example, churches will contain details including the name, denomination, pastor and source, while theaters only contain name information). However, all features in the map are linked to their respective master records in the Civil War Washington database. A hyperlink appears at the bottom of the context box, allowing users to connect directly to the associated record. Clicking this link will open a new internet browser window with the full place details.

Content

Figure 7: Clicking on a map feature will generate a context box with basic information about a place. Clicking on the URL link at the bottom will open a new internet browser window with the associated record in the Civil War Washington database, which contains all available information about a mapped feature. [Back to text.]

Activate time-aware data and use the time slider

Many of the mapped features are associated with temporal data that identify the beginning and end dates of the place. In many cases, beginning and ending dates are estimates, and in other cases, we have not been able to determine dates. Civil War Washington is actively researching time data for places represented on the map. To overlay time on the mapped data, click on the clock icon at the top of the application. Doing so will activate the time slider (see Figure 8).

Time Slider

Figure 8: The time slider is accessed via the clock icon. [Back to text.]

The time slider can be used in two ways: Users may watch the progression of features through time, or the data may be queried by selecting a specific time frame. To animate the data through time, simply click the play button located at the left side of the time slider window. The play button becomes a pause button during animation, allowing the progression to be stopped at any time. (Note: Although the time slider advances and data are updated accordingly, data points are still clickable and users are free to move about the map during the progression of time.)

Alternatively, the data may be constrained temporally by selecting a start time and end time in the time slider bar. To do so, click and drag out the sliding circle icon on the timeline (see example below). A second circle will stay at the original location while the clicked icon can be dragged to a different point in time. Both of these circles can then be adjusted to correspond to desired start and end times. As each circle is moved along the timeline, the corresponding date appears above, allowing for selection of specific beginning and end dates (see Figure 9).

Time Slider View 1 Time Slider View 2 Time Slider View 3

Figure 9: Adjusting the time slider for specific time ranges. In this example, the time slider end time is dragged to September 30, 1861, while the original is left at October 1860. Only those features that were active at some point between October 1860 and September 1861 will be drawn on the map in this setting. [Back to text.]

Draw, write, or measure on the map

The draw and measure tool, which allows for full customization of the view by adding text or drawing graphics onto the map, is located in the menu bar at the top of the screen and is accessible via the paint palette icon. Upon selecting the draw or measure tool, a handful of options appear in the context box, including fill color, opacity, outline, and outline width. In addition, for every draw option other than points and text, the "Show Measurements" box can be checked, which will display area or distance units for any shape drawn on the map. It is possible to specify the units of measurement for each shape by clicking on the drop-down menu for "Distance Units" (see Figure 10). These measurements will be displayed on the map, including on any printouts of the map, until the draw or measure tool window is closed or the "Clear drawings" button is selected. The "Clear drawings" option will not appear until something is drawn on the map, at which time the option will appear underneath the list of shapes.

Draw

Figure 10: The draw and measure tool offers a number of options for adding text or graphics to the map as well as for measuring both distance and area. [Back to text.]

Set and use bookmarks

The Civil War Washington map viewer allows site visitors to use bookmarks, which save the current view extent. The application will remember all bookmarks until the end of a session.

To access the bookmarks, click on the open book icon in the menu bar. The bookmarks menu will open. Some default bookmarks, such as for the White House and the Capitol Building, are pre-loaded. To add a new bookmark for the current map view, open the book icon in the menu bar and then click the open book icon with the green plus symbol within the bookmarks window. Give the bookmark a name and then click "Add Bookmark" (see Figure 11).

Bookmarks Bookmarks

Figure 11: The image on the left shows the default bookmarks, accessible via the open book icon in the menu bar. The image on the right shows the window for creating a new bookmark, launched from clicking the open book icon with the plus symbol from the initial bookmarks window. [Back to text.]

Print the current map view

To print the current map view, click on the printer icon in the menu bar at the top of the application window. A new window will open, which allows users to title and subtitle an image before printing.