This early 1950s "Television Play" was based on the 1940s stage play by John Patrick,
The Story of Mary Surratt. The play was produced and played a few weeks on Broadway.
You can download the script here:
https://archive.org/details/storyofmarysurra00patr
I have been looking for this old TV program - apparently it's available nowhere for viewing online - nowhere
that's reliable, that is! Several sites claim to a digital video available for download, but in checking, the sites are infected with malware and viruses - so beware!
We have a copy of Patrick's original script at the Hall Research Center. There used to be a community theater group in Clinton/Surrattsville during the 1950s, and I believe they performed the play at the local high school about 1960. The woman who played Mary Surratt later became a volunteer guide at Surratt House. One dared not mention the fact that Mrs. Surratt might have known something was going on because that lady would pull herself up to full stature and defend her character. She was the champion of Mrs. Surratt just like a certain Mudd granddaughter was for Dr. Sam - only there was no blood relationship in the case of the Surratt defense.