Who killed Cullen's wife in Hell on Wheels? He strangled the wrong man for it at the end of season 1

Cullen Bohannon spends all ten episodes of Hell on Wheels season 1 hunting one specific man. The finale lets him catch someone.

The setup arrives in the AMC pilot, which aired November 6, 2011. Bohannon (Anson Mount), a former Confederate captain from Meridian, Mississippi, came home from the war to a burned barn, a dead son, and his wife Mary hanging from the porch rafter. He had spent years believing she killed herself. Union Pacific foreman Daniel Johnson (Ted Levine), drinking with him in the Starlight Saloon, corrects that assumption at gunpoint: the soldiers who hit the farm were his men, and one of them — a sergeant — strangled Mary and strung her up to make it look otherwise. Bohannon asks for the name. Johnson declines.

"Well, it hardly matters now," he says — about four seconds before Elam Ferguson opens his throat with a sharpened knife.

That's the engine of the whole season. Johnson dies holding the one piece of information Bohannon came west for.

The names Bohannon already had

By the time he reaches Nebraska, he's been at this for months. A competency hearing in season 3 has a doctor read the tally into the record:

• Captain Ebert Nelson — formerly of the 13th Ohio, shot in Dayton in November 1865, four months after the war ended.
• Corporal Buckton Prescott — killed in a Washington, D.C. church, mid-confession, through the eye.
• Lieutenant Wuster and Lieutenant Tanner — both tracked down in Maryland.
• Captain Daniel Johnson — killed by Elam, not Bohannon, in the pilot.
• Sergeant Frank Harper — the last name on the list, and the one that matters.

Read more: How many seasons and episodes of Hell on Wheels are there? The full count

What happens in the finale

"God of Chaos" aired January 15, 2012. Thor Gundersen — the Swede — has found Harper at a trading post near Council Bluffs, Iowa, and is pouring him drinks. Harper produces a certificate of disability for discharge: born in Windsor, Vermont, farmer, enlisted January 1863, shot through the left abdomen at Starkville, Mississippi in June 1864, discharged July 18, 1864. Two weeks before Meridian. Gundersen doesn't care whether Harper was there. He cares that Harper can testify to federal marshals about Bohannon's motive for the other killings, and he puts him on a train with a protection detail.

Bohannon catches him during Durant's forty-mile-marker dance. They fight, Bohannon loses his revolver, Harper picks it up and starts insisting he has proof. Bohannon knocks the gun away and strangles him with his hands. The discharge notice is sticking out of Harper's pocket.

So who did it

The show never says. Johnson's word for the killer was "the sergeant," and Johnson is dead. Harper had the right rank, the right unit, and an alibi on paper. Nobody else is ever put forward.

Season 3 abandoned the question entirely. Incoming showrunner John Wirth said in 2012 that he was moving Bohannon away from the revenge motive that started the series and toward the work of building the railroad. The last thing the finale shows on the subject is Bohannon telling Elam he killed the wrong man, then riding out at sunrise — while the tarred-and-feathered Swede finds a poster offering $250 for his capture.

Earlier we wrote: In Gunsmoke, who did Matt Dillon marry? The full picture takes in the TV movies as well as the series