There's an S Donegan in the 1850 census listed as a barber in Springfield - could this be your Spencer?

Name: S Donegan
Age: 30
Estimated birth year: abt 1820
Birth place: Kentucky
Race: Black
Gender: Male
Home in 1850
(City,County,State): Springfield, Sangamon, Illinois
Page: 107
Roll: M432_127

Denise