Geospatial Data

The question refers to scanned images of traditional aerial photography film, and these scans are not georectified.
YES, Visit our National Geospatial Program page or call 1-888-ASK-USGS for our information package on digital cartographic data. 
The National Map small-scale collection, previously accessed through the National Atlas, offers plenty of choices in page-size maps.
Every flat map misrepresents the surface of the Earth in some way. No map can rival a globe in truly representing the surface of the entire Earth.
UTM coordinates are measured on the map by subdividing the 1000 meter grid squares into tenths or hundredths. This will narrow down the coordinate to a 100 or 10 meter square.
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.
That depends on what kind of reprojection you want to do. In some cases, if you want to reproject from one datum to another (specifically NAD 27 to NAD 83, or NAD 83 to NAD 27), a simple x-y shift will suffice.
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.
Generally, for the conterminous United States, the North American Datum (NAD) shift amounts to about 210 meters. This shift occurs because of the change in shape of the spheroid used to define the datum.