You can get a breeders NPIP certificate on the shipped birds that would be the future of your flock and start from there and you can documentation that the stock came from this particular breeder and so forth. You would need to leg tag them to ID them.
You can make your own pedigree of your birds by taking pics of them, write names and collect her eggs at each time with incubation process and go from there. I have a couple coop, enough for one roo and one hen and incubate their eggs only and tag the chicks when they hatch and so forth. That is how I did it.