Season three of “Hell on Wheels” finds Cullen Bohannon (Anson Mount) leaving his vengeance-seeking ways behind and investing in the new American landscape. The season opens in 1867, the third year of the building of the transcontinental railroad, and the beginnings of big business, big religion, and the new role of Wall Street in the White House. Bohannon must contend with racism, greed and murder as he single-mindedly leads the Union Pacific in its race across the country against the Central Pacific Railroad. The high stakes corporate race, the environmental costs and degradation of the native peoples’ way of life are themes that resonate deeply in today’s America. “Hell on Wheels” also stars Colm Meaney as Thomas “Doc” Durant, a greedy entrepreneur taking full advantage of the changing times, and musician/actor Common as Elam Ferguson, an emancipated slave working to achieve true freedom in a world entrenched in prejudice.