Skip to main content


Mason-Dixon Line
Society: ASCE Main Category: Civil Sub Category: Boundaries & Surveys Era: 1750-1799 DateCreated: 1767 Delaware Pennsylvania State: Zip: Country: USA Website: Creator: Mason, Charles , Dixon, Jeremiah

The granite milestones marking the Mason-Dixon Line bear crests from the two parties involved in the land-grant dispute, the families of William Penn and Charles Calvert (also known as Lord Baltimore). 

Image Credit: Original Image: Flickr/Padraic (CC BY-SA 2.0) Image Caption: Mason-Dixon Line Era_date_from: 1767
Cranetown Triangulation Site
Society: ASCE Main Category: Civil Sub Category: Boundaries & Surveys Era: 1800-1829 DateCreated: 1817 Kip's Castle Park Essex County State: NJ Zip: Country: USA Website: Creator: Hassler, Ferdinand

The precise system of measurements provided today by the U.S. Coast and Geodetic Survey originated with an act of Congress under the administration of Thomas Jefferson in 1807 that funded work on "an accurate chart" of America's coastal waters. Intended to aid sea-going commerce, the first work on this project, carried out in 1816 and 1817, helped establish a complex grid of geodetic reference points on which much of our land- and sea-based navigation now depends. 

Image Credit: Source: (National Oceanic and Atmospheric Administration) Image Caption: Cranetown Triangulation Site Era_date_from: 1817
Subscribe to Survey

We hope you enjoyed this essay.

Please support this 70-year tradition of trusted historical writing and the volunteers that sustain it with a donation to American Heritage.


Stay informed - subscribe to our newsletter.
The subscriber's email address.