What was the National Geodetic Vertical Datum of 1929 formerly known as?

The National Geodetic Vertical Datum of 1929 (NGVD 1929) was formerly known as the Sea Level Datum. This designation highlights its purpose, which was to establish a consistent reference for measuring elevations across the United States based on the mean sea level at various tide gauges along the coast. The datum was created to provide a standard reference for surveying and mapping, ensuring that elevation data could be compared and used consistently throughout the country.

In the context of surveying, height and elevation are crucial for a variety of engineering, construction, and geospatial applications, and having a common sea-level reference point has historically facilitated accurate vertical measurements. The NGVD 1929 later evolved into more refined datums as surveying technology improved, but its original title reflects the fundamental concept of using sea level as a baseline for elevation measurements.