Nested ItemsControl Orientation - wpf

Question

I have a nested ItemsControl. My data structure is an ObservableCollection of Campaigns which consist of a Campaign class and an observableCollection of Data counts (total, assigned, unassigned, closed). What I need is the following:
CAMPAIGN.NAME
TOTAL UNASSIGNED ASSIGNED CLOSED
CAMPAIGN.NAME
TOTAL UNASSIGNED ASSIGNED CLOSED
I am able to get the first part of this, but for some reason it will not honor the orientation for the second ItemsControl. What am I missing? My XAML is:
<ItemsControl x:Name="icCampaignChicklets" ItemsSource="{Binding CampChicks}" Grid.Row="1">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Vertical" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid x:Name="gridContent">
<Grid.RowDefinitions>
<RowDefinition Height="20" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<TextBlock x:Name="CampaignHeader" Height="20" Text="{Binding Path=Campaign.Name}" Grid.Row="1" VerticalAlignment="Top" TextWrapping="Wrap" HorizontalAlignment="Left" />
<StackPanel Grid.Row="1" Orientation="Horizontal" Margin="10">
<ItemsControl x:Name="icChicklets" ItemsSource="{Binding Path=Data}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border Width="150" Height="140" Background="{Binding Background}" Cursor="Hand"
MouseLeftButtonDown="Chicklet_MouseLeftButtonDown"
>
<Grid x:Name="gridContent" Margin="8,4">
<TextBlock Text="{Binding Caption}" Foreground="White" FontSize="17" />
<TextBlock Text="{Binding CountCaption, Mode=OneWay}" Foreground="White" FontSize="45" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="7" />
<TextBlock Text="Ú" Foreground="#99ffffff" FontSize="30" VerticalAlignment="Bottom" HorizontalAlignment="Right" Margin="3,5" FontFamily="Wingdings 3" />
</Grid>
</Border>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>

Answer 1

If you want to change the orientation of the contents of an ItemsControl, set its ItemsPanel property like so:
<ItemsControl
...attributes...
>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
Wrapping it in a horizontally-oriented parent StackPanel will merely arrange it and its siblings horizontally, but in this particular case it has no siblings.