Not to be confused with effectiveness and efficacy. For other uses, see efficiency (disambiguation). Efficiency is the (often measurable) ability to avoid wasting materials, energy, efforts, money, and time in doing something or in producing a desired result. In a more general sense, it is the ability to do things well, successfully, and without waste.
Marengo, Iowa. Marengo is a town in and the county seat of Iowa County, Iowa, United States. It has served as the county seat since August 1845, even though it was not incorporated until July 1859. The population was 2,528 in the 2010 census, a decline from 2,535 in 2000.
A Brief History. In 1851 the General Assembly of Iowa fixed the boundaries of Shelby County. The new county was named after General Isaac Shelby, who was famous for serving in the Revolutionary War, the War of 1812, and becoming the first governor of the State of Kentucky. Early settling in Shelby County began in 1848 in Gallandâs Grove. For more information about Shelby County and Its Courthouses, click here.