Julie:
I'm wondering if Baldwin and his wife died before 1850. I find a daughter "Margaret Scantland" b. about 1833 living with her maternal aunt, Ludica "Dicey" Reed Hamilton Chaney and her husband Thomas Chaney in the 1850 Census - Series M432, Roll 107 - Illinois - Gallatin County - Swawneetown Precinct - page 386 - Dwelling # 173 Household # 173 - taken September 10, 1850. There's also Andrew and Elmira Scantland and their children (Dwelling # 278) -- the only other Scantlands in the county.

Baldwin is listed as "Balwin J. Scandland" in the 1840 Census- Illinois - Gallatin County - Shawnee Township - page 13. Household composition: 1 male 10 - 15; one male 20 - 30; one male 30 - 40; one female under 5; one female 5 - 10; one female 20 - 30.

The Illinois Regional Archives Database marriages page is down right now, or I'd check to see what males and females got married in the county about that time (1840 - 1860).