The Labor Department says unemployment rates rose in 12 states and were unchanged in 16.
Nationally, unemployment slid to a four-year low of 7.7 percent in February, down from 7.9 percent in January. Since November, employers have added an average of 200,000 jobs a month, nearly double the average from last spring.
States hit hardest during the recession are showing improvement.
Florida's unemployment rate fell to 7.7 percent in February, down from 9 percent a year earlier. Nevada's rate, while tied with California and Mississippi for the highest among states at 9.6 percent, is down from 11.8 percent a year ago.