Trussell photograph collection

The Mason and Dixon Line (or Mason-Dixon Line) runs for 233 miles along parallel 39°43’ in the eastern United States, marking the boundary between Maryland and Pennsylvania. The line was surveyed by English astronomers Charles Mason and Jeremiah Dixon in 1763-1768 to settle property disputes between the Penns and the Calverts, proprietors of Pennsylvania and Maryland, respectively. Mason and Dixon also surveyed the boundary between Maryland and Delaware.

The line was marked with crownstones at 5 mile intervals, displaying the coat-of-arms of the Calverts on the south and of the Penns on the north side. Intermediate miles were marked with stones having an initial "M" facing Maryland and "P" facing Pennsylvania.

Dr. Allie L. Trussell (d. 1970) was an optometrist and history buff, a Virginia-born resident of the Hampden neighborhood in Baltimore. He developed a special interest in the Mason-Dixon Line in the late 1940s, leading him to travel nearly 30,000 miles a year to locate and document the stones which mark the line. In 1950 he was funded by the Maryland General Assembly and the State Board of Natural Resources to conduct a survey of markers on the portion of the line dividing Maryland and Delaware, working with Gwynn Reel, a physics student at the Johns Hopkins University. Trussell also spent time tracking down markers which had been removed to other locations, restoring them to their proper positions where possible, and making many photographs of them.