South Dakota

• As the fifth-smallest state in the country by population size, South Dakota grew at a rate of 7.9 percent between 2000 and 2010, adding 59,336 people to its 2000 population of 754,844. As of 2010, South Dakota's population stands at a count of 814,180 people.
  
  

Alaska

• Alaska ranks fourth from the top of the list of the five least-populated states in the United States with 710,231 residents by 2010, a 13.3 percent rate of growth that is one of the more robust rates of growth in the country. From its previous population of 626,932 people in 2000, the state added 83,299 citizens before the 2010 census.
  
  

North Dakota

• The cold Midwestern Great Plains state of North Dakota is the third-smallest state in the country by population figures, according to the 2010 census, with 672,591 residents in 2010. The state's population grew to its present size from its 2000 population of 642,200 by a rate of 4.7 percent.
  
  

Vermont

• The tiny New England state of Vermont is the second-smallest state in the union for population as of the 2010 census, but with a population growth of only 2.8 percent over the last decade it may well be the state with the smallest population in the country by the 2020 census. Adding only 16,914 citizens over a span of 10 years, Vermont's 2000 population of 608,827 increased to 625,741 in 2010.
  
  

Wyoming

• Although still the state with the smallest population in the country, Wyoming experienced one of the higher rates of population growth over the last decade, with a 14 percent growth. From its 493,782 population in 2000 to its population of 563,626 in 2010, Wyoming added 69,844 people over the decade.