In Western Union, Scott plays a reformed outlaw who tries to make good by joining the team building a telegraph line across the Great Plains in 1861.

Conflicts arise between the man and his former gang, as well as between the team stringing the wires and the Native Americans through whose land the new lines must run.

Facing considerable opposition to the line from Confederate soldiers, Indians, and outlaws, Creighton elicits the help of his sister Sue, foreman Pat Grogan, and assistant Homer Kettle.

Shaw and Blake are both attracted to Sue and vie for her attention, but their romantic rivalry is cut short when construction of the telegraph line starts on July 4, 1861.

After word arrives that the main camp is under attack by other Indians, the Western Union men rush back to help with the defense.

Forced to buy back their stolen horses from Slade, Creighton becomes suspicious of Shaw's involvement, especially when he admits to knowing the gang.

He helps rescue some of the Western Union men from the flames and burns his hands in the process (or so he lets everyone believe as he burnt them in the campfire).

In The New York Times, reviewer Bosley Crowther called the film "spectacular screen entertainment" and applauded director Lang's ability to take a "firmly-constructed fiction" and keep it interesting with "plenty of action and colorful incident.

Dean Jagger is the cool and determined chief engineer of the wire-laying gang—a portrait of the real Edward Creighton which does that gentleman worthy justice.

And Robert Young as a 'dude from the East,' Slim Summerville as a terrified cook, Chill Wills as a leather-skinned lineman and Virginia Gilmore as the unobtrusive 'love interest' are just four of a generally excellent cast.