With the Louisiana Purchase of 1803, the size of the United States was essentially doubled. Very little of this enormous expanse of land had actually been explored, let alone surveyed. In fact, at the time of the transaction, it was not known exactly how much land the United States had purchased.

The Louisiana Purchase Survey was first ordered by President James Monroe to begin shortly after the end of the War of 1812. This timing was due in part to the federal government’s desire to pay war veterans with land. War veterans were given land grants which entitled them to a certain amount of land depending on their status, but before they could claim a particular parcel of land, it had to be surveyed. Meanwhile, settlers were already beginning to stream into the west, so it became critical to survey the land as quickly as possible so that it could be either deeded to veterans or sold to settlers and land speculators.

To survey the Louisiana Purchase, the Public Land Survey System was adopted. This rectangular system had previously used to survey the lands in the Ohio River Valley. The official survey was begun in 1815 by two land surveyors, Prospect Robbins and Joseph Brown. The survey itself began in what is now Arkansas. Robbins and Brown marked their starting point using two pairs of gum trees, based on the tradition of using identifiable physical geographic features to mark survey points. This starting point, known as the Initial Point, was located in the middle of a hardwood swamp. Today, this landmark can be seen in the Louisiana Purchase State Park. Because these lands were surveyed first, they could be sold before other western lands, and eventually Arkansas became only the third state west of the Mississippi River to be admitted into the United States.

Working outward from the Initial Point, teams of surveyors working for the United States Engineers began marking township sections throughout the region. They began by surveying 60 townships’ worth of land (each encompassing six square miles) that could be sold immediately or given via land grants to veterans of the War of 1812. The use of the Public Land Survey System, which divided lands into townships and sections, was the direct reason why many land grants were 640 acres, or a “section” of land. The surveyors used only a compass and a chain, and the work was slow in the wilderness of this unsettled and unexplored territory. In fact, some areas were still not yet surveyed when Arkansas became a state in 1836.

Eventually, the Louisiana Purchase survey covered most of present-day Arkansas, Missouri, Iowa, North and South Dakota, and Minnesota. These surveys are continuous, spanning thousands of acres of land. Many of today’s state and country boundaries in this area follow the original survey lines, which is part of the reason why many states in this part of the country are nearly perfect rectangles.