Latitude and Longitude

Most survey marks were set by the US Coast & Geodetic Survey (now called the National Geodetic Survey) and information for those marks is available on the web.
If coordinates are to be passed on to another person it is technically necessary to report the horizontal datum and the latitude/longitude of the point (e.g.
The State Plane Coordinate System (SPCS) is a plane coordinate system (N-S and E-W lines are perpendicular) in which each individual state has from one to six zones, depending on the state's size and shape.
One system is no more or less accurate than the other. They are just two different ways of positioning a point. Many experienced users prefer UTM over latitude/longitude when using 7.5' topographic quadrangle maps.
One might confuse the difference between degrees/minutes/seconds and Decimal Degrees. To convert from decimal degrees to degrees/minutes/seconds with 45.63248 as an example: