Have been searching for awhile and cant seem to locate one, nor a detailed description of one they may have carried. Pennsylvania archives does not show they have anything related to this unit, nor have been able to locate anything in other museums, collections thus far.
A couple tattered flags of its sister units do survive (69th, 71st, 72nd PV) All that I have seen have the typical Pa seal in the center canton. But mostly interested in what or how the unit ID was indicated on the flag. Noticed that many of the Pennsylvania flags were sometimes abbreviated differently ie: Penn, Penn'a, or fully spelled out. Also this particular unit started its service as one of Bakers California Brigade Regiments as the "5th California Infantry"... but once he was killed at Balls Bluff, Pennsylvania reclaimed the units for its own quota of troops, and renamed/numbered them. At least one of the flags of the 71st Pa (If memory serves correctly) had both designations on the flag... "1st California Regiment", then above it on the next red stripe was placed "71st Penna Vol", assuming they just remarked and continued to use their originial, maybe not...
I will admit that Im not as well versed on resources on Federal flags... so my apology if I may have missed soemthing obvious out there... Appreciate any information or further guidance...
Respects
Frederick