Don't know anything about the Soyars family but do find an Issac O. Soyars in the Land Book (land ownership) for 1837 and 1838 with 135 acres on Lawsons Creek in Halifax Co., VA.
In the 1840 Land Book, my ancestor, Thomas Guthrie, had moved back to Halifax Co. from either Person or Caswell Cos., NC and owned that 135 acres, previously owned by Issac
Soyars. In the right hand margin of that listing for Thomas
Guthrie, it is noted as "from Issac O. Soyars by deed" so I feel certain the purchase was made in that year (1840). The
writing on that document wasn't the best in the world but it was readable as Soyars. I went back to the two previous
Land Book listings to double check that spelling and the name is properly ISSAC O. SOYARS. His latest birth date with land ownership in 1837 would have been 1816. Issac Soyars was not in Halifax Co., VA. according to the Land Books for 1841 and 1842 so I assume he moved elsewhere.