Root was born on a Massachusetts farm and worked as a bobbin boy in a cotton mill before switching, at the age of 15, to a Ware Massachusetts Machine shop. At age 24 he was hired by Connecticut industrialist Samuel W. Collins to work in his ax factory in Collinsville, a village of Canton, Connecticut. It was here that collins invented the technique of die casting metal.
According to historian Diana Muir writing in Reflections in Bullough's Pond, Root "reconceptualized," the making of axes. Until his invention, axes were made by "flattening wrought iron, folding it around a steel pin, and forging the two sides together under a trip hammer." Root arranged "a series of dies and rollers that could 'die forge' -or apply pressure to a mold, forming apiece of hot wrought iron into the shape of an ax, with an eye already punched to receive the handle." (Muir, Reflections in Bullough's Pond, p. 131)
According to Muir, Root next automated the tempering of axes by inventing a machine that moved ax heads through an temperature-regulated oven on a rotating wheel. And a machine that "shaved" the axes to give them a sharp edge, so that they needed only a small amount of finishing on a grindstone.
It was while working for Colt that Root perfected the Lincoln Miller milling machine, 150,000 of which were sold in the late 1800s, making it the most important American machine tool of the era. He modernized firearms production at Colt by designing state of the art drop hammers, boring machines, gauges, jigs, etc. Root also improved the milling machine invented by Simeon North and improved by the Robbins and Lawrence Company of Vermont and by Francis A. Pratt of the George S. Lincoln company in Hartford, Connecticut. The improved tool was known as the Lincoln Miller.
Diana Muir, Reflections in Bullough's Pond; Economy and Ecosystem in New England, University Press of New England, 2000