History of Surveying

When was the General Land Office (GLO) created, and what became of it?

Created in 1812 to manage the survey and sale of U.S. public lands. In 1946 it merged with the Grazing Service to form the Bureau of Land Management (BLM), which still administers the PLSS today.

What was the Domesday Book (1086), and why does it matter to surveying history?

A comprehensive survey of land, landholders, and resources in England commissioned by William the Conqueror in 1086. It is one of the earliest systematic land/property surveys — an early use of a survey for taxation and record-keeping.

Who were the Egyptian "rope-stretchers" (harpedonaptae)?

Ancient Egyptian surveyors who re-established field boundaries after the annual Nile floods. They used knotted ropes to measure distances and lay out right angles (a 3-4-5 knotted rope forms a right triangle) — an early form of land surveying.

What is a groma?

A Roman surveying instrument: a cross of two perpendicular arms with plumb-line weights, used to set out straight lines and right angles for roads, aqueducts, and centuriation (Roman land division).

Who invented Gunter’s chain, and when?

Edmund Gunter, an English mathematician and clergyman, introduced it in 1620. It standardized land measurement and tied linear measure directly to area.

What are the dimensions of a Gunter’s chain?

66 feet long, divided into 100 links of 7.92 inches each. 10 chains = 1 furlong; 80 chains = 1 mile; an area of 10 square chains = 1 acre.

Why is 66 feet such an important number in U.S. surveying?

It is the length of a Gunter’s chain. Because 80 chains = 1 mile (5,280 ft) and 10 square chains = 1 acre, the 66-ft chain elegantly links distance to area — which is why so many U.S. land measurements are multiples of 66 ft.

What was the Mason-Dixon Line, and who surveyed it?

A boundary surveyed 1763-1767 by English astronomers Charles Mason and Jeremiah Dixon to settle the dispute between the Penn family (Pennsylvania) and the Calvert family (Maryland). It later became symbolic of the divide between free and slave states.

What did the Land Ordinance of 1785 establish?

Adopted by the Confederation Congress on May 20, 1785, it created the rectangular survey system (the Public Land Survey System), dividing public land west of the original states into 6-mile-square townships before sale and settlement.

Was Thomas Jefferson president when the PLSS was created?

No. Jefferson championed the rectangular survey system as a member of Congress and led the committee whose work shaped the Land Ordinance of 1785. He did not become president until 1801 — the PLSS predates his presidency.

What is a PLSS township, and how is it divided?

A township is 6 miles square (36 square miles), divided into 36 sections of 1 square mile each. A standard section contains 640 acres.

Where did the first PLSS surveys begin?

In eastern Ohio. The "Point of Beginning" on the north bank of the Ohio River (1785-86) started the Geographer’s Line and the Seven Ranges — the first lands surveyed under the rectangular system, overseen by Thomas Hutchins, Geographer of the United States.

Which U.S. presidents worked as surveyors?

George Washington was a professional surveyor in his youth (appointed surveyor of Culpeper County, Virginia, in 1749). Abraham Lincoln also worked as a deputy county surveyor in New Salem, Illinois, in the 1830s.

How does metes-and-bounds differ from the rectangular (PLSS) system?

Metes-and-bounds describes a parcel by its boundaries — directions, distances, and monuments — and is used in the original colonies and other "state-land" states. The PLSS divides land into a regular grid of townships, sections, and aliquot parts, used in most "public-land" states.

What is a theodolite?

A precision optical instrument for measuring horizontal and vertical angles. Its refinement through the 18th-19th centuries greatly improved triangulation and boundary surveys; the transit is an American variant.

What was the U.S. Survey of the Coast (1807), and why is it significant?

Established under President Jefferson in 1807, it was the first U.S. scientific agency, created to chart the coast. It pioneered high-accuracy geodetic surveying in America and evolved into today’s National Geodetic Survey (NGS).