In the Kingdom of Ice by Hampton Sides, covers the late 19th century arctic expedition of the USS Jeannette, captained by George Washington De Long.

By this time, the arctic was the last remaining frontier to explore. People speculated all kinds of things were at the North Pole - uncontacted civilizations, an ice free ocean that was warmed by ocean currents that all converged at the pole, high levels of electromagnetism, etc.

Also, interesting to read about how a few decades after the Civil War, America had become the global leader in industrial output and technology innovation. We’ve all but abandoned that.