I believe I do know about Roswell B Chapman in Sunberry, Delaware County, Ohio 1820.
I think the "B" is a transcription error and the initial should be "R".I did look for actual Roswell B Chapmans to rule out and the only one I found would have been only 6 yrs old in 1820.
Roswell Riggs Chapman, on the other hand would have been 22 or 23 in 1820 (consistent with the census info).His wife Phoebe Stanbery Chapman would also have been about 22 (consitent with the census).The two children on the census I know nothing about (my ancestor Albert Stansberry Chapman was not born until 1823 and I have no information on his siblings).
A reasonable history of Roswell Riggs Chapman and two generations of descendents can be had from the entry for his son Albert S. Chapman in the Union County History:
His death actually occurred 13 Dec 1827 in or near Natchez, MI due to consumption (tuberculosis). The circumstances, date, location and cause of death are described in the Union Co. history cited above.This date, location and cause of death are further substantiated by the sexton's records of Natchez, MS:
Many years after his death, his wife married Dr. Arius Kilbourn of Worthington, Ohio and she is buried with him in Lot 241, Section A, Walnut Grove Cemetery, 5561 Milton Ave, Worthington, Ohio under the name Phoebe C. Kilbourn (same munment as her husband). Her parents are in the grave just to the right of Arius.When I have a chance I will put the photos up at "Find-a-grave" but until then, the records and inscriptions are shown in the Worthington Cemetery database here (remember Phoebe is Kilbourn (no "e") and her parents are Stanbery (not Stansberry as her descendents came to spell it)):