Look at a map of the world. Where North America and South America connect there is only a narrow strip of land between the Atlantic Ocean and the Pacific Ocean. That skinny piece of land is called the Isthmus of Panama. For the past 400 years people have wanted to dig a canal through it. If ships sailing between East and West could go through a canal right there, they would not have to go all the way around the end of South America. The trip could be shorter by thousands of miles.

It took over 30 years and cost a lot of money to dig a 50-mile canal through the swamps, jungles and hills of Panama. Even worse, many of the people working on the canal died from sicknesses. But by August 1914 the Panama Canal was ready to let steamships through. Some people called the canal the “World’s Greatest Engineering Work.”

Here is a selection of images on the machines and men involved in building the canal, from the archives of Scientific American from 1881 to 1920, with modern captions.

Acknowledgement: Many thanks to Kevin McGarry and his 8th grade Social Studies students at P.S. 49, the Dorothy Bonawit Kole School in Queens, N.Y., for field-testing this slide show, and Principal Anthony Lombardi for facilitating.