Metes and Bounds: The 1632 Maryland Charter

#30DayMapChallenge 2026 - Day 3: Polygons

When kings granted land on the other side of the world, they had to describe the boundaries in human-readable text, much as we still do today with the "metes and bounds" of a property. In 1632, Charles I granted the charter for the new colony of Maryland to Cecil Calvert, 2nd Baron Baltimore. The charter included a verbose, landmark-by-landmark description of a polygon.

This map breaks down the key verbiage of that description and annotates the map to show what each passage describes.

📜 Read the full text of the Maryland Charter

Why it doesn't match today's Maryland

You'll notice right away that the charter's language doesn't line up with Maryland's present-day boundaries.

• The northern border was disputed with Pennsylvania. Penn's later charter overlapped Maryland's claim to the 40th parallel, which runs north of Philadelphia. After decades of conflict, the dispute was settled by the Mason–Dixon Line, surveyed in the 1760s at about 39°43′ N.
• Delaware as we know it didn't exist yet. The charter's description includes the land along Delaware Bay, which was later claimed by Pennsylvania (via William Penn) and eventually became the state of Delaware.
• Which branch of the Potomac? Today's southern border follows the North Branch of the Potomac. The South Branch is longer, though, and could be argued to be the "first fountain" the charter refers to. That reading would have put a large piece of what is now West Virginia inside Maryland.

Learn more about Maryland boundary disputes

About this map

Lines and were hand-drawn by the author in squidmaps from known points and combined into a concave hull polygon with help from Claude (Anthropic).

Current Maryland boundary polygon: Maryland GIS Data Catalog