When newfangled motor shovels threaten to take their place, Mike Mulligan promises that he and his trusty steam shovel, Mary Anne, can do a hundred men's work in one day.
Mike Mulligan was sure that his steam shovel, Mary Anne, could dig more in one day than 100 men could dig in a week! But one trerrible day- they lost their job. Desperate for work, Mike offeres to dig the cellar for Popperville's new town hall for free- unless he and Mary Anne could do the job in just one day! Can they really do it? The whole town comes to see.
When Mike Mulligan and his steam shovel, Mary Ann, lose their jobs to the gasoline, electric, and diesel motor shovels, they go to a little country town where they find that one new job leads to another.