A steam shovel is a large machine that digs and moves earth using a huge metal bucket attached to a mechanical arm. Powered by a steam engine (which burns coal or wood to heat water and create steam pressure), these machines could scoop up tons of dirt, rocks, or coal in a single bite and swing around to dump it into railroad cars or trucks.

Steam shovels revolutionized construction and mining in the late 1800s and early 1900s. Before them, digging big projects like canals, foundations, or mines meant hiring hundreds of workers with hand shovels, which took years. A single steam shovel could do the work of fifty laborers. When workers built the Panama Canal (connecting the Atlantic and Pacific Oceans through Central America), steam shovels carved through mountains and jungle, moving millions of tons of earth.

The machines looked like mechanical dinosaurs: a house-sized body on tracks, with a long boom extending forward and a massive bucket hanging from cables. An operator sat in a cabin controlling levers that made the bucket bite into the earth, lift, swing around, and dump its load.

Though diesel and electric excavators replaced them decades ago, steam shovels captured people's imagination. Virginia Lee Burton's beloved children's book Mike Mulligan and His Steam Shovel tells the story of an old steam shovel proving it can still dig as well as newer machines.