When Langrishe is sitting in the theater with the dying Chesterton, their dialogue is taken from King Lear, Act 4, Scenes 1 and 6. It is a conversation between Gloucester, who has been blinded, and his son Edgar, who leads his father to the edge of a tall cliff. Langrishe and Chesterton take a few liberties with the text. They skip some lines, and swap roles partway through.
Jack Langriche mentions "Claudia and the Countess have embroidered the tabs in gold: Thalia and Melpomene". Thalia and Melpomene are two of the nine muses. The two are the muses of comedy and tragedy, respectively. The two often represent the theatre.
During the scene in the Bullock home, in which Seth (Timothy Olyphant) and Martha (Anna Gunn) argue, David Milch wanted Olyphant to more emphatically deliver his line as he puts his coat on and storms out. Milch finally instructed him to put his coat on "like a flaming homosexual" before leaving.
While talking with Al, Langrishe compares attacking George Hearst to harpooning a whale, and mentions "the sleigh-ride that follows." He is referring to a Nantucket sleigh-ride, an experience known to 19th-Century whalers in which, when a whale is harpooned from a small boat, the whale would try to escape, dragging the boat through the water by the harpoon-rope until it became exhausted.
This is the second time that a character played by Powers Boothe has faced Wyatt Earp. Boothe played Curly Bill Brocius in Tombstone (1993).