On 8 May 1862, she was attached to the 91st's hospital, as Matron.
She is listed as present on the May-June Hospital muster roll, but is apparently not listed on any other muster rolls.
[sources: 1, 2]
1index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania
(Mary B Roberts)
[compiled military service record, 91st Pennsylvania Infantry, Mary B Roberts]
[transcribed 8 April 2015, from two images obtained from the National Archives and Records Administration]
Roberts, Mary B.
Co. -, 91 Pennsylvania Inf.
Matron | [blank]
[the rest of the card numbers are blank]
Number of personal papers herein 0
Book Mark: [blank]
See also [blank]
R | 91 | Pa.
Mary B Roberts
[blank], Co. [blank], 91 Reg't Pa. Infantry.
Appears on Hospital Muster Roll
of 91st Reg't Pennsylvania Infantry.
for May and June, 1862.
When attached to Hosp. May 8, 1862
How employed Matron
Book mark: [blank]