In the early days (from 1785) of the United States, provisions were made to subdivide territorial lands into townships and sections thereof, along lines running with the cardinal directions of north-south, east-west. Later, as additional lands were added to the public domain, such lands were subdivided in a similar manner.

However, these methods of subdividing lands do not apply in the eastern seaboard (original 13 states) and in Hawaii, Kentucky, Tennessee, Texas, and West Virginia. For laws regulating the subdivision of public lands and the recommended surveying methods, check the instruction manual published by the Bureau of Land Management, Washington, D.C.

For many years the triangulation and traverse monuments of various domestic and foreign survey agencies have been defined by their geographic positions; that is, by their latitudes and longitudes. Property corners might be definitely fixed in position in the same way. The necessary computations are involved, and too few land surveyors are sufficiently well versed in the theory of geodetic surveying for this method to attain widespread use. In recent years, plane coordinate systems have been developed and used in many states and in many foreign countries. These grid systems involve relatively simple calculations, and their use in describing parcels of land is increasing. Every state in the American Union is now covered by a statewide coordinate system commonly called a grid system.

As with any plane-rectangular coordinate system, a projection employed in establishing a state coordinate system may be represented by two sets of parallel straight lines, intersecting at right angles. The network thus formed is the grid. A system of lines representing geographic parallels and meridians on a map projection is termed graticule. One set of these lines is parallel to the plane of a meridian passing approximately through the center of the area shown on the grid, and the grid line corresponding to that meridian is the Y-axis of the grid. The Y- axis is also termed the central meridian of the grid. Forming right angles with the Y- axis and to the south of the area shown on the grid is the X-axis. The point of intersection of these axes is the origin of coordinates. The position of a point represented on the grid can be defined by stating two distances, termed coordinates. One of these distances, known as the X-coordinate, gives the position in an east- and -west direction. The other distance, known as the Y-coordinate, gives the position in a north- and- south direction; this coordinate is always positive. The X -coordinates increase in size, numerically, from west to east; the Y -coordinates increase in size from south to north. All X -coordinates in an area represented on a state grid are made positive by assigning the origin of the coordinates: X = 0 plus a large constant. For any point, then, the X -coordinate equals the value of X adopted for the origin, plus or minus the distance (X) of the point east or west from the central meridian (Y -axis); and the Y -coordinate equals the perpendicular distance to the point from the X -axis. The linear unit of the state coordinate systems is the foot of 12 inches defined by the equivalence: 1 international meter = 39.37 inches exactly.

The linear distance between two points on a state coordinate system, as obtained by computation or scaled from the grid, is termed the grid length of the line correcting those points. The angle between a line on the grid and the Y -axis, reckoned clockwise from the south through 360, is the grid azimuth of the line. The computations involved in obtaining a grid length and a grid azimuth from grid coordinates are performed by means of the formulas of plane trigonometry.

A property description by metes and bounds might include points located by coordinates as follows:

"Commencing at U.S. Coast and Geodetic Survey Monument Bradley, Va, having coordinates y = 75,647.13 ft and x = 35,277.48 ft, as based on the Virginia Coordinate System, North Zone, as are all the coordinates, bearings, and distances in this description; thence S 3630E, 101.21 ft to the intersection of Able Street and Baker Avenue, whose coordinates are y = 75,565.77 ft and x = 35,337.45 ft, . . . ."

In many counties and municipalities the land of the community is divided into subdivisions called blocks, tracts, or subdivisions. Each of these subdivisions is further subdivided into lots. Blocks and tracts usually have numbers, while a subdivision usually has a name. Each lot within a block, tract, or subdivision usually has a number.

From data obtained in a tax map survey, or cadastral survey, a map book is prepared that shows the location and boundaries of each major subdivision and of each of the lots it contains. The map book is filed in the county or city recorders office, and henceforward, in deeds or other instruments, a particular lot is described as, for example, "Lot 72 of Tract 5417 as per map recorded in book 72, pages 16 and 17, of maps, in the office of the county/city recorder of [named] county/city"; or as "Lot 32 of Christopher Hills Subdivision as per. . . ."