The practice of mechanical mowing is less than 200 years old; before our modern era, grassy areas were maintained by grazing animals (in fact, sheep, in particular, are still used across the globe for this purpose). Turf was also maintained in earlier times with hand-held scythes for cutting and brooms for sweeping.

An English engineer named Edwin Budding invented the first mechanical mower in 1827. His prototype lawn mower was inspired by a carpet-trimming machine in a textile factory. The basic principle used in his mower is still found today in reel mowers: curved blades produce a cutting action alongside a stationary steel plate. The first machines, designed by Budding, were so heavy that they required three people to operate. Draft animals were also used to pull the first lawn mowers.

Manufacture of lawn mowers for general use began in the 1860s. By 1862, John Ferrabee (who bought the rights to manufacture lawn mowers from Edwin Budding) was making eight models in various roller sizes up to 36 inches. His company manufactured over five thousand machines until production ceased in 1863. Gasoline-powered mowers finally became available to a wide market in the 1920s when Colonel Edwin George popularized Moto-Mowers, built in a Detroit factory.

This information is summarized from Fundamentals of Turfgrass Management, by Nick Christians: Ann Arbor Press, Chelsea, Michigan: 1998, (chapter 8) and Wikipedia: http://en.wikipedia.org/wiki/Lawnmower.