Farmers grew hemp during WWII to help supply the military with rope. Each farmer was allowed one permit to grow ten acres. About 40,000 acres were cultivated in Iowa, part of the 300,000 acres cultivated nationwide. At the time, corn was fetching between $30 and $40 per acre compared to $100 to $150 per acre for hemp. The plants grew up to fourteen feet tall.

A dozen hemp processing plants were built in the "Hemp for Victory" era in Iowa, including in Algona, Humboldt, Emery, Grundy and Eagle Grove. Most of the operations were closed in 1945. Three years later, the $350,000 Humboldt plant was purchased for one dollar by a local man and used as a National Guard armory until 1980. The Emery hemp plant, once acquired by Lifetime Industries for motor home construction, traded hands several times until it was finally abandoned in 1973.

The following short history was included in a 1996 story published in The Des Moines Sunday Register ("Revival of hemp industry at hand"):

"Hemp was a major crop in the southeastern United States until the mid-19th century, when cheaper imports began arriving. But it became a vital crop in the Midwest, especially in northcentral Iowa, as World War II cut off overseas supplies.

A 1943 report in The Des Moines Register notes: 'Growing the weed as a crop looked a little silly to some farmers at first. Many were skeptical. They had known hemp only as marijuana, a harmful narcotic, a weed smoked by drug addicts.'

The report continued: 'Government men told farmers the war had cut off imports of Manila hemp and sisal fiber' and that 'farmers need not worry about growing a narcotic.' By the end of the war, more than 4,000 Iowa farmers were growing hemp on tens of thousands of acres, with prices guaranteed by the government.

Herbert Howell, a farm management specialist at Iowa State University from 1934 until 1973, said in addition to promoting hemp production, the government set up about a dozen hemp processing plants in Iowa during the war."

Evidence of Iowa’s industrial hemp farming past dots the rural landscape. In addition to the old hemp processing facilities are the hemp plants themselves. The Scott County Sheriff's Reserves reported that every year they cut down and burn between 15,000 and 20,000 wild marijuana plants in Scott County alone. Sheriff Dennis Conard acknowledged that the wild "marijuana" plants, descendants of those cultivated by Iowa farmers to make rope during World War II, could be dried and smoked, but they wouldn't produce a "high," as they do not have the potency of marijuana plants cultivated for illegal drug use.