The “Create Thiessen Polygons” tool create one polygon around each data point in a point feature class, which may be useful if there is a limited number of points. To create more manageable districts for larger data sets, the “Dissolve” tool can be used to merge Thiessen Polygons (see part 1 about this tool here) into larger polygons.
The Dissolve tool is located under “Data Management Tools” in the “Generalization” toolbox, and create features based on one or more specific attributes. This means that when setting the parameters for the tool in the popup box for this tool, you choose input layer, define output feature class and you can choose which field to perform the tool on. Features that share the same value for the selected field will be dissolved into one feature and the written to the output feature file.
The image below show the output feature class after running the Dissolve tool on the Thiessen Polygon layer from an earlier post.
See part three of this series here.