I love H. Beam Piper’s sci fi stories, and I always wanted to map out the Terran Federation. Well, there’s not enough source material for any kind of reliable map, but I’ve collected as much info as I could without re-reading every book:
The chart is probably self-explanatory; it maps distance and in a few cases directional relationships between the planets. Some planets are mentioned without any other info, those are free-floating boxes. These are not complete, there are a few planets mentioned by name that are not on my schematic yet.
And as a PDF: piper-systems PDF
There is some material I did not check yet, so this will get updated eventually. And do let me know if I you are aware of any data not included yet!