This overview essay by SCE Professor Erik J. Chaput provides context for the drafting of the letters from Dorr to his mother Lydia. The essay provides a brief description of Dorr's treason trial, his sentencing and the nature of his imprisonment in the state prison on the Providence cove.
The Dorr Rebellion Project http://library.providence.edu/dorr
The Dorr Letters Project http://library.providence.edu:8080/xtf/index.html
.pdf (text searchable)