The fictional plot, starring James Dunn, Mae Clarke, and David Manners, pits two friends and future brothers-in-law on opposite sides of the North–South conflict, dividing their families and threatening their survival.

Lieutenant Kenneth Reynolds and his good friend, fellow naval officer Raymond Jordan, go ice-skating with their girls in anticipation of being called to war.

Meanwhile, at a government war council discussing the secession of six Southern states to form the Confederacy, two officials from Virginia are asked to declare their loyalty to the Union.

A similar loyalty test confronts Raymond, who does not want to be separated from his fiancée, Captain Buchanan's daughter Julie, and leaves to join the Confederates in Virginia.

He cannot find another job because everyone considers him a traitor, so he goes to help his uncle John Ericsson complete his new design of USS Monitor, an ironclad warship.

Kenneth encourages his uncle to submit to the government his design of the ironclad Monitor, which features a unique revolving gun turret.

Though the Navy has accepted the plans of Bushnell, another shipbuilder, Commodore David G. Farragut smooths things over and helps everyone see that the Monitor is a better choice to engage in battle with the enemy.

It noted that there is no historical record of a Kenneth Reynolds assisting John Ericsson in his design of the USS Monitor, but it appreciated the "sentimentality" which this plot device contributes to the story.

It explained that supporters of both the North and South would leave the film thinking that their side won due to "the triumph of diplomacy and photography".

This review called the battle scenes generally accurate historically, aside from the sailors standing on the deck of the Minnesota cheering for the Monitor during the fight.

[15] An Associated Press news item commended the "unexpectedly good" on-screen action, though it felt the film was "handicapped by an unexciting title".

In his 1996 book The Blue and the Gray on the Silver Screen, Kinnard writes: Hearts in Bondage contains some capable artists, a plot that sometimes intrigues, plenty of production and numerous actionful moments.

It does, however, laud director Ayres, who "performs miracles on a tiny budget", and the special-effects team, led by Howard and Theodore Lydecker, who constructed the scale models of the ironclads used in the "exciting and convincing" battle scenes.

[12] Reinhart opines that while Frank McGlynn Sr. provides a close likeness to Abraham Lincoln, his scenes fall short because they are not based on historical fact.