This survey indicated that the block books actually consist of at least three distinct, though often overlapping series. This series begins in 1851, and appears to be incorporated within our film series MSA CM196. This series runs from 1888 to 1913, and is incorporated into our series MSA CM196. This series begins in 1918, and appears to correspond to our film series MSA CM197. The block books serve as a supplementary index to the Baltimore City land records, showing conveyances of city property on a block by block basis.
Every block is assigned a unique number.
These numbers are shown on block book plats, which serve as a finding aid to the block books. Once assigned a number, blocks do not appear ever to have been renumbered, although they were often subdivided with sequential alphabetical suffixes being added to the base block number. Every transfer of property within a block is supposed to be noted under that block's number. Individual entries give a reference to the land record volume in which the actual instrument was recorded. The Archives collection of block books consists of 312 reels of 35mm film.