According to the Dictionary of American Family Names edited by Patrick Hanks, DODSON is an English patronymic form of DODD and DOTSON is an English patronymic form of the personal name Dudde (Dodd). Often, in America these names are spoken and written interchangeably, particularly by other people.
There were several Dodson//Dotson families in Colonial America, particularly in Maryland and Virginia.
There was a two volume book published in 1988, THE DODSON/DOTSON FAMILY OF NORTH FARNHAM PARISH, RICHMOND COUNTY, VIRGINIA) by Rev. Silas Lucas and Mrs. Sherman Williams. Many Dodson/Dotson researchers have located these books and used them in their family trees. In some cases, the lineages are correct and in others the lineages are mis-attributed.
With the help of DNA testing, particularly, Y-DNA testing and this surname project the correct lines can be verified and the mis-attributed lines corrected.