Working in watertight caissons required breathing compressed air. Surfacing too quickly caused nitrogen bubbles to form in the blood, a painful condition known as the bends.

After a deadly panic caused by rumors of a collapse, Barnum used his circus animals to publicly demonstrate the new suspension bridge could easily hold immense weight.

The Brooklyn Bridge was the first suspension bridge to use steel wire, which offered a significantly higher tensile strength than traditional iron to hold the massive spans.

When her husband became bedridden with decompression sickness, Emily studied advanced mathematics and engineering to successfully relay his daily instructions to the workers.