How To: Create a region or boundary map with no internal boundaries.
This article describes how to create a region map without internal boundaries using the dissolve function of the GeoProcessing Wizard. The article uses the states theme found in the esri\esridata\usa directory as an example.
To create the region map, you must dissolve the features base on an attribute in the theme table. The dissolve will combine all of the features with the same value into one feature without internal boundaries. The states theme used in this example contains a Sub_region field you will use to dissolve the features.
Add states.shp from the esri\esridata\usa directory to the View.
Load the Geoprocessing extension. a. Select Extensions from the File menu. b. Turn on Geoprocessing and click OK.
Select GeoProcessing Wizard from the File menu to launch the GeoProcessing Wizard.
Select Dissolve features based on an attribute from the list of GeoProcessing options and click Next.
Select states.shp as the theme to dissolve.
Select Sub_region as the the attribute to dissolve.
Click the browse button next to the Output File to name and save the output theme.
Select any additional attributes you would like to summarize or aggregate and click Finish.
Symbolize the states theme with unique values based on the Sub_region field.
a. Double-click the new dissolved theme to open the Legend Editor b. Select Unique Value for the Legend Type. c. Select Sub_region for the Values Field. d. Select the color scheme or the colors you want to use for each region. e. Click Apply and close the Legend Editor.