You can use text evidence to back up what type of interpretation you have of a theme. Like the theme “Challenge’s can be overcome with hard work and patience” if your interpretation of the theme is that the theme Challenge’s can be overcome with hard work and patience means that when you have obstacles and challenges that you need to overcome. Having patience and being doing hard work can help you overcome your obstacles/challenges. Then you can give an example by using text evidence. There are plenty of other ways to use text evidence to support an interpretation of a theme as well.
The description of setting in paragraph 7 of "The Legend of Sleepy Hollow" is important to the theme of America's changing history in that it depicts Sleepy Hollow as a "drowsy" place caught in the past while great "currents" of change go on around it.