This 1915 article from the Littleton Independent shows that the U.S. government had interest in cannabis as a medicine even as some states around the country had begun to ban it as an illicit drug. Not only were they interested, they were growing it themselves. An excerpt:
"A medical drug plant farm on a large scale -- a thing unique in the annals of horticulture in the country and abroad, has been established by American scientists on the Virginia hills just opposite the national capital."
Pretty intriguing way to start off an article, eh? We thought so as well.
It seems that the Department of Agriculture authorized and encouraged the farm at the time (apparently, the department test field in Arlington wasn't big enough). The 45-acre fields were on the property of John B. Henderson, Jr. -- possibly the son of U.S. Senator John B. Henderson, who retied in Virginia near the Capitol after serving as a Missouri Senator from 1862 to 1869.
Along with cannabis, the farm cultivated ginseng, larkspur, golden seal, Japanese peppermint, senega (an expectorant), colchium (used for treating gout) and sprigella. There's even this little cartoon of a drug farmer:
Unfortunately, we couldn't find much else on this issue aside from "Drug Plants Under Cultivation," a grow manual put out by the USDA in 1927. The publication includes chapters about cannabis-growing that were originally published in 1915 -- presumably all information gleaned from cultivating the marijuana at the "drug plant farm".
Interestingly, many of the methods in the report are still applicable today:
"About half the seeds will produce male plants, which must be removed before their flowers mature, otherwise, the female plants will set seed, thereby diminishing their value as a drug," the report states. "The male plants can be recognized with certainty only by the presence of stamens in their flowers."
It goes on:
"Ordinary stable or barnyard manure plowed in deeply is better for use as a fertilizer than commercial preparations and may be safely applied at the rate of 20 tons per acre. Good results may be obtained, however, with commercial fertilizers, such as are used for truck crops and potatoes, when cultivated in between the rows at the rate of 500 or 600 pounds per acre. When the female plants reach maturity a sticky resin forms on the heavy, compact flower clusters, and harvesting may then be begun. The tops of the plants comprising the flower clusters are cut and carefully dried in the shade to preserve the green color as far as possible. Drying can best be done, especially in damp weather, by the use of artificial heat, not to exceed 140° F."