The February rate was well above the nation's 8.1 percent rate. The dramatic increase from January's 10.3 percent moved the state's joblessness to levels not seen since March 1983 in another sign of the state's dire economic straits.
Those have been playing out as $1.1 billion has been cut from the state's $7 billion budget since July and legislators are battling with Gov. Mark Sanford over using federal stimulus cash to piece together a budget and spare public schools, colleges, health care and public safety programs from losses.
Sanford spokesman Joel Sawyer was reviewing the data and said he would comment later.
The Employment Security Commission said Friday the state has 241,000 unemployed, up 15,000 from January. If those were all living in one county, they'd rank as the state's sixth-largest.
Allendale County had the highest unemployment rate at 23.4 percent. It was one of five counties with a fifth of the workforce out of work.
Lexington County had the lowest rate at 7.9 percent and was the only county in the state with a lower jobless rate than the national average.
Meanwhile, the number of people on jobs in South Carolina has fallen by 88,700 in year as manufacturers have shed 23,500 jobs. But the recession has cleaved into the ranks of white collar occupations, too, with professional and business services losing 16,200 positions.
Sanford has said much of the unemployment problem comes from growth in the state's labor force. The commission says the labor force increased by nearly 5,600 in February.