Searching through some scanned documents, I came across an old photocopy from a book that I must have found years ago - not properly cited. My citation reads "1850 Mortality Schedule for State of Indiana" - no author, no date and no idea what repository I found this in.
Listed on page 47 is a typed list of the mortality schedule for Madison County, Indiana, the 68th District, page 30 that lists my ancestor, William Shaw, husband of Mary (Heck) Shaw.
William Shaw, age 50?, male, married, born in Pennsylvania, died September, Farmer, Bronchitis, sick 300 days.
Also listed on the same page was a Mary Shaul, 6 months, female, born Indiana, died December, Arcipales, sick 30 days.
I will need view the actually mortality schedule to obtain a proper source, but at least this gives me a clue as to when William died and the cause.