The Iowa unemployment rate dropped to 2.6 percent in July, the lowest level in 18 years, Iowa Workforce Development said today. Employment has grown by 13,200 since a year ago, when the unemployment rate was 3.1 percent. The U.S. unemployment rate was 3.9 percent last month. Total Iowa employment increased to 1.64 million, an increase of 5,200 workers from June. The number of people without a job dropped to 44,000 in July from 44,900 in June. Last year, 52,100 were without work. Total nonfarm employment fell by 700 jobs, with retailers shedding 3,000 jobs. Meanwhile, manufacturers added 1,300 jobs and the construction industry added 300, the sixth consecutive month of job growth in the sector. Iowa was one of 11 states to register a drop in its unemployment rate last month, the U.S. Department of Labor said.