How was Geodetic data calculated prior to the establishment of WGS 1984 using satellites?

Answer 1

Surveyors would use physical benchmarks and standardized measuring tools, such as the chain, vara, and compass. In the United States, a central point was established as the benchmark for describing all other locations in the CONUS by the NAD 1927 datum.

Keep in mind this wasn't as accurate as the technology developed the last few decades. NAD 1983 is considered more correct than NAD 1927, but the difference between the two can be several yards. Today, land is measured using precise distance/ angle measurements, but often in relation to extremely accurate control points.