Defining the Line

By Morgan Stashick, College of Engineering



The bold line representing the boundary between Alabama and Florida on a map seems precise, but the exact location of the state's border is not as established as it seems. An original state line, called the mound line, has been forgotten over the years, but is being rediscovered by Auburn civil engineering faculty member Larry Crowley and part-time Auburn instructor Milton Denny, a well-known land surveyor.

The earthen mounds that marked the original Alabama-Florida line were formed in 1799 by prominent land surveyor Andrew Ellicott, who earlier surveyed the planned federal city of Washington, D.C. He positioned these mounds at approximately one-mile intervals to mark the location of the 31st parallel treaty boundary established by a joint U.S.-Spain boundary commission. A 124-mile segment of these mounds identifies the Alabama-Florida boundary between the Conecuh and Chattahoochee Rivers.

"Ellicott and his surveyors built mounds to mark the boundary, but there has been a lot of confusion about where they are," says Crowley. "In fact, there were actually two lines established between the Conecuh and Chattahoochee rivers. One was a guideline of tree blazes that the survey party placed while following a surveyor's compass due east, which Ellicott believed would result in a straight line. However, that line was one mile north of the intended boundary at the Chattahoochee River.

"Ellicott then calculated the proportional offsets that needed to be measured south along the guideline to locate the intended boundary at the 31st parallel. Later, when public lands were to be surveyed and sold, there was confusion about which of the two lines was actually the state boundary. The initial surveyors for Alabama selected the wrong line the northern line on which to base their surveys. This left a sliver of land in Alabama that was initially surveyed as part of Florida."

The first maps of the mound locations were produced by the U.S.-Spanish boundary commission in 1800. In 1846, a joint Alabama-Florida boundary commission was tasked to resolve which of the two boundary lines represented the true boundary, and it was determined that the southern line was correct. In 1854, a survey was again conducted along this southern mound line to locate, reference and map the existing mounds with measured references to adjacent public land surveys.

From copies of these maps, Crowley and Denny calculated the mound locations by using a United States Geological Survey digital quad sheet as a reference. They took their calculations to the field, following a hand-held GPS to locate several mounds.

"Nearly all of the mounds along the original border have been left unmarked, because they are located in isolated fields, along dirt roads and within wooded forests," says Crowley.

Crowley and Denny led a workshop in Andalusia, Ala., where six surveyor-led teams were sent into the field along a segment of the boundary line with potential mound locations. Newly located mounds were documented for the State of Alabama to update with survey-grade GPS, permanently marking the Florida-Alabama boundary at these locations.

"Before the workshop, only two mounds were known to have been located along this segment," says Crowley. "Now, a total of 25 mounds have been marked."

In March, Crowley and Denny plan to hold more workshops to expand their search for mounds along the western end of the U.S.-Spanish boundary, which today is the border between Louisiana and Mississippi.

"Ultimately, our plan is to draw up a map and have it available in county courthouses along the state boundaries, so the information is obtainable for surveyors and landowners in that area," says Crowley.

As a footnote, the inaccurately surveyed land was annexed from Florida to Alabama in 1900, finally forming Ellicott's intended boundary. Today, a concrete marker is being placed on each site to identify its location and historical significance. Ellicott's earthen monuments still serve as the "legal testimonials" of the first state boundaries even those that have been found again in somebody's backyard.


Last Updated: Aug. 17, 2011

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