Elizabeth I checked the 1840 census for Prince George's and Sarah was listed as head of house hold. I found no other Mattingly's in that county. MALES: under 5 = 1; 20 to 30 = 7; 40 to 50 = 1 FEMALES: 20 to 30 = 1; 40 to 50 = 1 Free Blacks MALE: Under 10 = 1; 10 to 24 = 1; 24 to 36 = 1 FEMALES: Under 10 = 1; 10 to 24 = 1