Help Montgomery County, Maryland solve a mystery. They are trying to figure out what the "P." abbreviations stand for on a Martenet & Bond 1865 map of the county.
The map was produced by S.J. Martenet & Co. in Baltimore. The "P" appears next to the names of property owners. It could mean "principal", "plantation", "place", or something completely different. The company does not know because their records were lost in the Great Baltimore Fire of 1904. Here is another example image with the "P"'s after some of the Dr. Washington Duvall lands.
This post was largely stolen from the Montgomery County Planning Blog.