This Obelisk markes the Mason Dixon Line and the “West” line when it is intersected by York Rd, in northern Baltiomore Co. What is this “West” line? The mason dixon line extends beyond this line and is broadly defined as the boundary between south and north. The West line is specifically Northern border of MD with Pennsylvania. It is a straight line at constant lattitude, 15 miles south of the southernmost point of Philadelphia. You may remember from here, that the border with PA used to run up into modern Philadelphia, and after many disputes this was ruled the final location and was then marked by Mason and Dixon.
This is not one of the original Mason Dixon markers, which were squat little pieces of white rock placed every mile along the line with the letter M on the Maryland side and P on the Pennsylvania side. Every five miles, Mason and Dixon would put down a major marker with sheilds representing each state on them. You can see one of those in the link above.
So what is this marker? Well it certainly comemorates the Mason Dixon line, but it was placed there at a later date by the Pennsylvania highway department. I’ve always enjoyed going past this obelisk on the way to PA, but I can’t tell you why. Perhaps that is becasue this monument was the first of its kind that I had ever seen. I’ve crossed over the m-d line hundreds of times and I think that when I first crossed at this point, it was the only time I had ever seen a monument erected for a border. It was interesting and it sort of brought a mundane crossing into a higher level of significance.
Also of note, I took the picture from Maryland. The markings on the obelisk show you which state you are going into. On the other side, in PA, you would see the word, Maryland.
