"Teaching with Colorado's Heritage"
Module 10: Using Maps with Students

A map is a picture, or visual representation, showing places and their relationships to each other. Not only do maps show space and location, but they also show location during a specific period in time. Comparing and contrasting maps can show how an area or population has changed over time. Therefore maps are useful tools for historians and students of history, and can be used for many types of research.

Complete the following exercise to learn how maps are useful tools for understanding the history of a particular area:
Understanding the past: what factors lead to the urbanization, growth, and/or decline of US cities?

Types of maps

• A base map is a general-purpose map, showing the locations of land and water.
• Topographical maps are used to illustrate 3-dimensions of a base map by using graphical features such as contour lines to indicate elevation.
• Relief maps use color or shading to illustrate 3-dimensions. More information on topographical map symbols is available from the USGS.
• A thematic map is a special-purpose map, primarily portraying information on a single topic or a set of topics. It may feature cultural information, such as population, or physical information, such as annual rainfall.

Many specific types of maps are actually a combination of base and thematic, such as:

• Political maps, showing cultural features like the outlines of countries, states, and cities.
• Physical maps, showing natural features such as mountains, rivers, lakes, and shorelines.
• Road maps, showing major and minor highways, cities and towns, often with campgrounds, parks, and other tourist features.

Features on a Map
Most maps have the following features, which are important to note during analysis (Stephens).

• Title
  Title of a map tells the reader "what," "where," and "when" about the map.
• Source
  The source or author often gives insight about its intended purpose and reason for creation.
• Scale
  A map represents a portion of the earth's surface. Mapmakers can't draw maps the same size as the area they represent or the maps would be too big. So they draw features smaller than they actually are. Scale is the relationship between distance on the map and distance on the ground.The scale is usually located in the legend box of a map, which explains the symbols and provides other important information about the map.
  
  A map scale usually is given as a fraction or a ratio of map distance to ground distance, such as 1/10,000 or 1:10,000.
  This means that 1 unit of measurement on the map—1 inch or 1 centimeter—represents 10,000 of the same units on the ground. If the scale were 1:63,360, for instance, then 1 inch on the map would represent 63,360 inches, or 1 mile, on the ground. The first number (map distance) is always 1. The second number (ground distance) depends on the scale.
  
  A large scale map shows a limited area, but a large amount of detail. A small scale map shows an extensive area, but a small amount of detail (Rosenberg, M. 2004).
• Orientation
  Orientation shows the geographic location in relation to something else, and often includes compass direction. By convention we place north at the top of the map, but this has not always been so throughout history. The orientation of a map often indicates the importance given certain physical features depicted on the map. Maps of the Holy Land typically had east at the top. Maps with the south at the top show an Australians' point of view.
• Legend
  Maps use certain conventions such as symbols to display a lot of information in a small area. The map legend contains the list of symbols used on a map, indicated by a sample symbol with an explanation showing what feature that each depicts, such as house, church, school and other cultural features.
• Grids
  Many maps include the lines of longitude and latitude to help place the map in its geographic location on the globe.

Place names and how they change overtime
Analyzing place names on maps can provide a lot of information about the place, such as human settlement patterns, sovereignty, land use and landscape. For example:

• Place names such as New England, New Mexico suggest the culture of the people who settle there.
• Jonesboro and Johnstown reflect prior ownership or residence.
• Names such as Sheep Waller Gap reflect the use or prior use of an area.
• Name such as Slick Rock Creek and White Cliffs reflect the natural features and landscape of an area.

Activity
To discover how settlement of and sovereignty over places affect the content of maps throughout history, use the map The United States of America Laid Down from the Best Authorities, Agreeable to the Peace of 1783 which was drawn the year the Treaty of Paris officially ended the Revolutionary War. Find evidence of British rule in place names (such as Williamsburg, Baltimore, Lancaster). Find evidence of Native American settlements in place names (such as Chingoteak Island, Pocomoak Bay, Potoromack River) You might also discover the absence of Washington, D.C., on the map, and discuss how American self-government would change features of the map in the future.(Library of Congress Collection Connections: Map Collections 1500-2004).

Bias
As in any human creation, maps have bias. They are an interpretation by the map author of a particular location, and can be manipulated in many ways to represent what the author wants to be represented. Think about ways the following features can be manipulated by the author and why: scale, orientation, place names and legend. Determining the map's intended audience may help to sort out the purpose of the maps creation and possible bias.

Panoramic Maps (also called Bird's-Eye Views)
Panoramic maps, published at the end of the 19th century, are useful maps to analyze to learn about bias in maps. Panoramic maps may look different then what we generally consider a map, but they are considered maps because they show spatial relationship. These maps were developed by local Chambers' of Commerce during the progressive era to to portray the city in question as prosperous, growing and modern. Points to consider when analyzing a Panoramic Map:

• What is the relationship between the commercial and industrial sections?
• What is the status of the map - published? manuscript?
• What annotations are present?

Activity

• Analyzing Panoramic Maps from the Library of Congress' American Memory Map Collection

Analysis Guides
This Map Analysis Worksheet from the U.S. National Archives and Records Administration is a useful tool to use when analyzing maps.

This How to Read Historic Maps Analysis Sheet from the Newberry Library is a good guide for analyzing historic maps.

Extension: Viewing Maps
You will usually need no special viewers to view maps as they are often presented in .gif or .jpg formats, which your Internet browser automatically displays. However, there is a special technology called MrSID (Multi-Resolution Seamless Image Database) by LizardTech allows you to zoom in and out of an a specific portion of the map.

The Library of Congress has an extensive map collection. "MrSID" opens automatically with any map in the Library of Congress collection (it does not require any downloading, etc.). Accessing Maps at the Library of Congress and Using MrSID is an overview to help you find what you want in the Library of Congress.

To use MrSID outside of the Library of Congress collection, the maps must be in .sid format to view and you must install the free viewer on your machine: ExpressView Browser Plug-in

References
Rosenberg, Matt. 2004. Map Scale. http://geography.about.com/cs/maps/a/mapscale.htm. 10/09/04.

Stephens, D.T. Making Sense of Maps. History Matters. http://historymatters.gmu.edu/mse/maps/. 10/03/04

Zoom into Maps. 08/07/04. Library of Congress. http://lcweb2.loc.gov/ammem/ndlpedu/features/maps/introduction.html. 10/03/04.

Collection Connections: Map Collections 1500-2004. 02/12/04. Library of Congress. http://memory.loc.gov/ammem/ndlpedu/projects/map/thinking.html. 10/02/04.