One of the 71st Pennsylvania's flags were captured at the battle of Ball's Bluff. That is the only flag I have found so far from that battle.

There is a two book series on Pennsylvania flags, "Advance the Colors" by Richard Sauers. That series was a huge help for me, as I track all captured Union flags. Mr. Sauers listed a few flags that are unknown at what battle they were captured. Most likely he used the Pennsylvania state adjutant records when the war ended.

Hope I was somewhat helpful!

Have a good day,

Shawn Prouty