Early maps of the Americas were crude, based on observation and approximation of distances. As settlements became more entrenched in the New World and competition for land increased between the French, English and Spanish, the methods and precision of the land surveys also improved; surveys and mapping were now conducted by professional surveyors and cartographers. These high quality maps were valuable to their respective countries, as they could advance the position and land claims of each country with a stake in the New World.
Cartographers and surveyors in Colonial America attempted to use the established European methods, but they were thwarted by the vast wilderness that the New World presented them with. Instead of using a theodolite, a surveyor’s tool used to mark the position of a celestial object on the horizon as a measuring marker, Colonial surveyors instead came to rely on the circumferentor, or surveyor’s compass, because it was more portable and much more usable in densely wooded than the bulky and cumbersome theodolite.
As settlers pushed farther and farther inland, and the population of the Colonies swelled, there became an even greater need for accurate surveys and maps. All sorts of boundaries needed to be set and verified, from individual land plots, to county and state borders, to official boundaries between different European colonies. From this need a new group of surveyors emerged – the colonial landowner. They were educated, and the best way of solidifying their own properties and holdings was to have accurate surveys of their own regions in place. Notable examples of landowner-turned-surveyor include George Washington and Thomas Jefferson.
Individual colonies also employed independent surveyors to verify landowner surveys as well as conduct surveys on behalf of the government. These individuals were very well respected and admired, and the position of Surveyor-General became a very desirous for upward-climbing member of Colonial society, especially in the larger cities such as New York and Philadelphia.
Perhaps the most famous example of surveying in Colonial America was performed by two men brought over from England to settle a border dispute. Charles Mason and Jeremiah Dixon were brought in to survey and make official the border between Pennsylvania and Delaware, and also end the disputes over the land between the Penns of Pennsylvania and the Calverts of Maryland. Mason’s specialty was astronomy, and Dixon’s surveying, and they not only brought with them expertise and impartiality, they also brought with them new technology. The zenith sector, which observed the passage of stars crossing the meridian near the zenith, and a new field clock, loaned to them by the Astronomer Royal of Great Britain, which was far more advanced than anything the Americans had in their possession. The final line was established on October 7, 1767, and was more than 233 miles long. Even more important, the new technology and techniques Mason and Dixon introduced to the American surveyors would change and improve the methods they used when surveying.
When the initial settlers and surveyors arrived in the New World, they had no idea the challenges and terrain they would face in trying to carve a nation out of a wilderness. But the efforts of these early cartographers and surveyors have shaped the nation we know today.