I’m not sure how much of a mystery the death turned out to be, but this story would seem to indicate that Union troops were finally getting paid and sending remittances back to their loved ones.
From a Seneca County, New York newspaper on February 7, 1863:
Sudden Death.
Mrs. ANN RYAN, an Irish woman, died very suddenly at the house of Martin Mortimer, in this village, on Wednesday morning. The circumstances attending her death have excited the suspicion of the authorities, and an investigation is now going on before Justice Clark.
Mrs. RYAN has been an inmate of the County House for some time past. A few days since she received a letter from her husband, who is a member of the 3d New York Artillery, stating that she would find an allotment of $20 at the Auburn Savings Bank, for her use. On Tuesday she went to Auburn, drew the money, and during the day returned to this village. In the evening she went with Mrs. Mortimer to several different places to do some trading, after which they both returned home. Some time during the night Mrs. RYAN died, the Mortimers alleging that her death took place about 3 o’clock on Wednesday morning, and that for some time previous she appeared to be in great distress from long and continued vomiting. She was buried on Wednesday by the Overseer of the Poor. The whole affair will be thoro’ly investigated.