More than 120,000 pounds of hemp fiber was needed to rig the 44-gun USS Constitution, America’s oldest Navy ship affectionately called “Old Ironsides.”

Nearly 55 tons of fiber was needed for the lines and rigging on that USS Constitution alone. Even more hemp fiber went into making canvas for sails and caulking for the wooden hull.

Where did all of that hemp fiber come from? It came from the cannabis sativa fields of patriotic Revolutionary War-era farmers who originally grew the fibrous crop for the British Crown. Strong fibers formed strong nations in the pre-industrial age, and hemp was strategically important during the Revolutionary War.

Yet, hemp is no longer purposefully grown in the U.S. in any significant amount. The forgotten history of this lowly “ditch weed” – now hugely important as a food for migratory birds – reveals that hemp was an important crop from Colonial times through World War II, when it was last widely planted across the country for the war effort.

British colonies compelled by law to grow hemp

Hemp arrived in Colonial America with the Puritans in the form of seed for planting and as fiber in the lines, sails and caulking of the Mayflower. British sailing vessels were never without a store of hemp seed, and Britain’s colonies were compelled by law to grow hemp.

Hemp was the fiber of choice for maritime uses because of its natural decay resistance and its adaptability to cultivation. Each warship and merchant vessel required miles of hempen line and tons of hempen canvas, which meant the Crown’s hunger for the commodity was great. Ship captains were ordered to disseminate hemp seed widely to provide fiber wherever repairs might be needed in distant lands.

Hemp: Important crop for colonial farms and The Republic

By the mid-1600s, hemp had become an important part of the economy in New England, and south to Maryland and Virginia. The Colonies produced cordage, cloth, canvas, sacks and paper from hemp during the years leading up to the Revolutionary War. Most of the fiber was then destined for British consumption, although at least some was used for domestic purposes. Ironically, the first drafts of the Declaration of Independence were penned on hemp paper.

Hemp fiber was so important to the young Republic that farmers were compelled by patriotic duty to grow it, and were allowed to pay taxes with it. George Washington grew hemp and encouraged all citizens to sow hemp widely. Thomas Jefferson bred improved hemp varieties, and invented a special brake for crushing the plant’s stems during fiber processing.

Shortly thereafter, Robert McCormick (father of Cyrus McCormick, who invented the first successful reaper) patented a hemp fiber-processing device. Through the International Harvester Co., Cyrus’ descendants later contributed additional labor-saving harvesting tools to hemp farmers in the 20th century.

Florida, Missouri, Illinois and Kentucky farmers key in 19th century hemp industry

Hemp crops quickly spread, and arrived in Kentucky with settlers from Virginia just prior to the Revolutionary War, according to a 1919 article in the Kentucky Agricultural Experiment Station Bulletin no. 22. These settlers set the stage for what would become one of the most important and long-standing hemp industries in America.

Along with Missouri and Illinois, Kentucky farmers produced most American hemp until the late 1800s, when demand for sailcloth and cordage began to wane as steam ships dominated the seas. By the end of the Civil War, Kentucky was the only state with a significant hemp industry until World War I, and that state remained the nation’s leading producer of hemp seed.

International Harvester Company: Mechanizing the hemp harvest

In 1918, virtually all stages of hemp growing and processing in the U.S. still relied on hand labor. In Nebraska, a mechanical fiber-processing machine had been tried, but the resulting fiber was not of the quality desired by the growers, so they imported laborers to process it the age-old way: by hand. In 1919, G.W. Schlichten was awarded a patent for a fiber-processing machine called a decorticator. This machine looked promising but, for unknown reasons, never went into production.

It took the directed efforts of Wisconsin State Department of Agriculture and local hemp growers like Matt Rens of Waupun to convince the International Harvester Co. and others to embrace the task of mechanizing the hemp harvest and processing.

Matt went on to build a highly successful hemp-milling business that included several plants, and contracts with Wisconsin farmers for thousands of acres of hemp. His steam-driven mills were the state-of-the-art in hemp processing through the 1950s, and one of his employees played a role in building another important hemp-processing machine that turned the stalks where they lay in the fields during the retting process.

Politics and synthetic fibers: Downturn of the American hemp industry

Despite those new hemp-handling tools, which lowered production costs, the demand for high-quality domestic hemp fiber steadily declined after World War I. Kentucky still produced much of the hemp seed and Matt’s Wisconsin mills produced most of the fiber.

Ultimately, hemp’s use as a fiber crop was crippled by politics. In 1937, the federal government passed the Marijuana Tax Act, aimed at regulating the narcotic varieties of cannabis. Interestingly, this law turned over the regulation of hemp production to the Department of Revenue, which was then responsible for licensing all hemp growers.

“(The Marijuana Tax Act) didn’t really affect us as growers, other than we had to pay a small tax and sign a paper stating that we wouldn’t use the plant as a drug,” explains hemp farmer and Matt’s nephew, Junior Prange. “What really killed the hemp industry in the 1950s was the availability of cheap synthetic fibers.”

One Last Boom: WWII-era Hemp for Victory campaign

World War II brought on the final burst in American hemp-fiber production. The USDA’s Hemp for Victory campaign successfully convinced growers to again embrace hemp. The federal government consulted with Matt and embarked on an ambitious project that involved construction of many new hemp processing plants.

But before the project was fully realized, the war ended, along with demand for domestic hemp fiber. Many Midwestern towns (and farmers) were left high and dry with empty or partially constructed plants, and cancelled hemp contracts. By 1958, the last significant hemp crop in the U.S. had been harvested and processed.

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