According to Bureau of Labor Statistics (BLS) provisional estimates, in July 2003 the seasonally adjusted civilian labor force in Maryland numbered 2,937,100, with approximately 135,300 workers unemployed, yielding an unemployment rate of 4.6%, compared to the national average of 6.2% for the same period. Since the beginning of the BLS data series in 1978, the highest unemployment rate recorded was 8.7% in January 1982. The historical low was 3.5% in January 2000. In 2001, an estimated 6.5% of the labor force was employed in construction; 6.8% in manufacturing; 5.6% in transportation, communications, and public utilities; 17.6% in trade; 5.8% in finance, insurance, and real estate; 28.8% in services; 21.9% in government; and 1.4% in agriculture.
Baltimore was a leading trade union center by the early 1830s although union activity subsided after the Panic of 1837. The Baltimore Federation of Labor was formed in 1889, and by 1900, the coal mines had been organized by the United Mine Workers. In 1902, Maryland passed the first workers' compensation law in the US; it was declared unconstitutional in 1904 but was subsequently revived. The US Department of Labor reported that in 2002, 346,000 of Maryland's 2,460,000 employed wage and salary workers were members of unions. This represented 14.1% of those so employed, up from 13.8% in 2001 but down from 16.1% in 1998. The national average is 13.2%. In all, 415,000 workers (16.9%) were represented by unions. In addition to union members, this category includes workers who report no union affiliation but whose jobs are covered by a union contract.