Unknown Johnson who married Elizabeth Evans born 1765 in S.C.

Hi, I am trying to find information on Unknown Johnson who married Elizabeth Evans born 1765 in S. C. They had a son named Beverly Johnson. When Unknown Johnson died Beverly was very young and Elizabeth remarried a Timothy Dunn born 1755 in S.C. I don't know if Timothy adopted Beverly or Beverly just went by the surname Dunn. Thanks in advance for any information on Unknown Johnson.

Dianne Snyder Rutherford