If you look at a map of Maryland and West Virginia. You will see the western border of Maryland is a nice straight line North to South meridian, except for 3 little right angle jogs. One seems to be only about 300 - 500 feet. I have looked at court decisions on the "Fairfax Line" but I have not found any explanation on these little jogs. There seems to be no physical reason or town or road. To me it is a curious question as to why there is not a straight North to South surveyed border. There is one East to West (Mason-Dixon) Line. Any thoughts?
In 1748, the Virginia House of Burgesses and the King-in-Council set the meridian running North from the Fairfax Stone as the boundary between Virginia and Maryland. This was not surveyed and marked until 1788, when it was done by one Francis Deakins, commissioned to do so by the Maryland Assembly.
Unfortunately, the "Deakins Line" is not straight, nor is it an accurate meridian. However, it became the accepted border between the states. There were lawsuits over this when the inaccuracy was discovered, which were eventually resolved by the US Supreme Court in 1910, in Maryland vs. West Virginia, by keeping the Deakins Line, since it had been the de facto border for a long time. Deakins does not appear to have been deliberately inaccurate, since his errors deprived Maryland, who were paying him, of territory that should have been theirs according to the original decisions.
To find more about this, give your favourite search engine "Deakins Line", and expect to find a lot of articles about interesting local history.