WPF combobox value and display text

I'm used to doing things like

State.Items.Add(new ListItem { Text = "SomeState", Value = NumericIDofState });

Where State is a Listbox in ASP.NET.

How do i achieve the same with a WPF ComboBox? I do see a property called 'Content' in the ComboBoxItem object but how do i assign each item a value other than what's displayed to the user? Please help.