U.S. National Geodetic Survey was created in 1807.

Emery I. Balazs has written:

'Corrections applied by the National Geodetic Survey to precise leveling observations' -- subject(s): Leveling, National Geodetic Survey (U.S.), National Geodetic Survey (U.S.).

Plain surveying means the survey in which earth surface is considered as to be flat or plain i.e. its curvature is ignored.

Geodetic survey is the survey in which curvature of the earth is taken into count and then surveying is done.

in plane survey the surface of earth assume as plane or straight its uses as limited distance where as in geodetic survey surface of earth assume as curve its use in long distance.

Plain surveying means the survey in which earth surface is considered as to be flat or plain i.e. its curvature is ignored.

Geodetic survey is the survey in which curvature of the earth is taken into count and then surveying is done.