Curious about Irish immigrant and Boss Tweed's trusted lieutenant,  General Brendan Donovan? Read Donovan's correspondence with a friend, written during his tour as a brigadier general in the Union Army. Liam, This month has proved to be a particularly savage time for our forces.  More of our men have been struck down in the past three days than during the entire span of the Mexican campaign.  The sheer depth of the brutality is something to behold -- beyond anything we witnessed as young men -- and forcing one to question what sort of injury these young minds endure as they bear witness to such horror. I tell you, my friend, the fields down here are sewn with bodies -- bloated and bursting -- left to lie fallow until the cart of some poor soul finally arrives to carry them away.  If they arrive at all.  It is a different world. What we once found exhilarating in our boyhood now appears senseless on such a scale as this. Consider yourself fortunate to be home, retired from this life, away from the turmoil of war. Until the eve when you and I may toast each other once more, I remain your brother-in-arms, Brendan Watch Brendan Donovan's official introduction to Five Points in the season premiere of 'Copper,' airing this Sunday, June 23 at 10/9c, only on BBC America.