Government Documents and Microforms Department

Creating a District of Columbia Wards Map

 This demonstration illustrates how to download a D.C. map of wards and how to add a new field to the table so that new data may be displayed.

Part 1.  Downloading D.C. wards map layer file from esri.com

Step 1.   Go to http://www.esri.com

2. Choose the Products tab at the top left of the menu.  Scroll down to Data.

 Choose Data.

3.   From the Data page, choose Downloadable Data under the Browse, Subscribe, Download section.                                                 

4.   Scroll down and choose Census 2000 TIGER/Line Data.

5.   Choose Download Data.

6.      Under Select a State, choose District of Columbia from the drop down list.

7.      Click the Submit Selection button.

8.      Under Select by County, choose District of Columbia Voting Districts 2000. Click the Submit selection button directly under the Select by Layer window.  See next graphic.

Click Here

9.      Click the box next to District of Columbia.

10.  Click the Proceed to Download button.

11.  Click the Download File button.

12.  Choose the save button and choose the place on the hard drive you want the file to be saved.

13.    Example:  Save in C:/Temp.  It will be saved as: at_tigeresri………..zip.  This is a zipped file so you will have to unzip it before it can be used with ArcView.  If you do not have the Winzip software, you can download an evaluation copy from: http://www.winzip.com/     Open WinZip.  Choose Use Evaluation Version unless you have purchased the software.  Choose Next.  Choose unzip or install from an existing zip file.  Choose Next.  The file that you just downloaded should be at the top of the list. 

You can also check the date and time under the Modified section to determine which is your file.  Choose Next.  Highlight the file name and click Next.  Choose Unzip Now.  A window will appear containing the unzipped files.  Right click on the vot….file and choose Open with WinZip. Click Next.  Choose no to the prompt: Do you want to add the folder…Choose Unzip or install from…Choose Next.  Choose Unzip Now.  Close the window.  The unzipped file should be in the folder: C:/ unzipped.

 Part 2.   Displaying D.C. wards layer and adding data

  Step 1.     Open ArcGIS 9  

2.        Click on the yellow Add Data button under Help at the top.  In the Look in window, go to the C:/unzipped folder and double click on the file: vot0011001.  It should look like this: tgr11001vot00.shp.  Double click on it to add it as a map layer.

3.     Change the layer name.  Double click on the layer name (tgr11001vot00.shp), to open the Layer Properties window.  Click on the General tab and type the new name in the box.

           Click Ok. Now the new name appears in the legend window.

Part 3.    Adding a new field and data to the layer’s table.

  Step 1.    Right click on the layer name and click on Open Attribute Table.

          Click on the Options button and choose Add Field.  Type the name of the field.   Click Ok. The new field is added to the table.

Step 2.  Choose the Editor button just above the Layers window in ArcView 8.x.

              Click Start Editing.  Now you can enter numbers in the rows within the field.

               In this example, the numbers of services are random and for demonstration only.  Once you have entered the data, click on the Editor button and choose Stop Editing.                                                                                                                                                                                                                  

Step 3.  You may now display the data that you added to the table.

Part 4.   Displaying D.C. “Services” data along with ward numbers

Step 1.      From the ArcView display window, right click on the wards layer. Scroll down and             choose Properties.

Step 2.      From the Layer Properties window, choose the Labels tab.

Step 3.      Click the Expression button. If the Name field is not already in the large window, double click on it in the top window to add it.  Double click on the new field name in the top

window to add it to the large window.  Add a couple of spaces between the quote marks to separate the two labels. Press Ok.

Step 4.  Now the ward number and “services” number can be displayed simultaneously.

Right click on the Wards layer name.  Scroll down and click on Label Features.  The wards and the services numbers are added to the map.

One can readily see that ward 1 has 4 service sites, etc.

For more information contact Timothy Cash at: casht@georgetown.edu