-LRB- CNN -RRB- -- Utah is the nation 's fastest growing state , increasing 2.5 percent from July 2007 to July 2008 , according to new population estimates from the Census Bureau . Barack Obama greets one of the newest members of the U.S. population this year on the campaign trail . The main reason for Utah 's growth is a `` natural increase '' -- births minus deaths -- said Census Bureau demographer Greg Harper . `` Utah has a strong rate of natural increase and domestic migration , where more people move into the state and -LSB- are -RSB- not moving out , '' he said . `` Second is Arizona , '' Harper said . `` It grew by 2.3 percent , and the increase is due to domestic migration , meaning more people are moving into the state than moving out . Also , it 's a natural increase , more people were born there than died . '' Arizona is followed by Texas , North Carolina and Colorado , each with a 2.0 percent growth rate . Texas added more people than any other state -- about 500,000 -- making it the third-fastest growing state . Because it has a larger population size , its percentage growth was less than Utah . `` Nevada was last year 's fastest-growing state , but it fell to eighth , '' said Harper . `` Overall , that state had been among the four fastest-growing states each of the past 23 years . '' Only two states lost population : Michigan and Rhode Island , losing 0.5 and 0.2 percent respectively . Overall , Northeastern states are not growing as fast as other parts of the country , but they have been on the increase since 2005 . The South added the most people during the period , 1.4 million . But Western states , with a 1.4 percent increase , saw the fastest growth rate . One state that has reversed its course of growth is Florida . A few years ago more than 250,000 people per year were moving there . But for 2007-2008 , the state 's 0.7 percent increase was below the nation 's 0.9 percent overall increase . According to the estimates , the United States had a net gain of just over 2.7 million people from July 2007 to July 2008 .