Symbolizing layers

For this map, we want the state boundaries to serve as outlines for the counties, so if it's not already on top, bring the State Outline layer to the top of the Drawing Order.

Beneath each of the map layers in the Contents pane is the legend for that layer. At this point, each layer has only a single symbol:

1. Click once on the colored box for State Outline in the Contents pane to reveal the Symbology pane. The Symbology pane is where you set the display characteristics of map features:

We want to see both the state boundaries and the counties, so let's change the properties of the States symbol to display just the outline. Switch to Properties on this pane if it is not already there.

1. Set the Fill Color to No Color. Set the Outline color to Black. The preview at the bottom of the pane will update. Click Apply to update the map with these changes.

Let's make one change, to make the state boundaries stand out from the county boundaries. Right now, the line thickness Outline width) is 0.7 pt, the same as in the Counties layer. If we leave it at this width, the only distinction from the county boundaries is that it may be slightly darker, which might be difficult to determine. Let's change that.

1. Change the thickness to 2 by clicking the up arrow or typing 2 in the box to the right of the Outline width box. Click Apply to update the map.
   The outline will now appear much thicker, perhaps even too thick. As you gain familiarity with the software, you'll get a sense of how thick lineweights should be, but know that they may appear slightly different on the screen than they will when printed. In fact, lines in particular appear thicker in the Map View than they do in Layout View.
2. If the Symbology pane is still open, click on the Counties symbol; otherwise, repeat the previous steps to open the pane for the Counties layer. Change the Fill Color to White. Leave the Outline color and width for the moment. 
3. Click Apply to update the map and close the Properties window. Your map should now resemble the US Counties map shown in the following section.