You can search all the transcripts in the Houston Oral History Project.
The results will list any interviews that contain your search words.
You may then select a specific interview from the list to search its transcript.

When you access a specific interview, you can play the video once the play interface appears. You may also scroll along through the transcript on the right pane and search the text using the "Find on page" search box.

At intervals throughout each transcripts you will see the following icon: . You may click on this icon to jump to the corresponding place on the video track.