South Dakota (USA) is 2.8 times larger than Ireland.
Area: 70,273 km2 World Factbook
Population: 4,832,765 (July 2014) World Factbook
Ireland, also commonly referred to as the Republic of Ireland, is a sovereign state in Europe occupying about five-sixths of the island of Ireland. Wikipedia
South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux Native American tribes. South Dakota is the 17th most extensive, but the 5th least populous and the 5th least densely populated of the 50 United States. Wikipedia