Source: U.S. Bureau of Labor Statistics  

Release: Employment Situation  

Units:  Thousands of Persons, Not Seasonally Adjusted

Frequency:  Monthly

People are classified as unemployed if they meet all of the following criteria: they had no employment during the reference week; they were available for work at that time; and they made specific efforts to find employment sometime during the 4-week period ending with the reference week. Persons laid off from a job and expecting recall need not be looking for work to be counted as unemployed. The unemployment data derived from the household survey in no way depend upon the eligibility for or receipt of unemployment insurance benefits.

The series comes from the 'Current Population Survey (Household Survey)'.