The valley, along with much of southern Afghanistan, has been the site of many American-led development projects during the Cold War and post 9/11-era. These projects have mostly been managed by USAID.
USAID's reports from the various decades create a historical geography of Afghanistan. These reports can be fun to read when one reads them for the historic geographic picture they paint. Fortunately, Richard Scott, a former USAID official who was in Helmand during the 1970s, has a large collection of original documents from USAID's efforts dating from the 1950s to the present. The website has economics of agriculture production, surveys of land and people, opium production information, and so much more.
If one is interested in learning about an area of Afghanistan where much of the action is then these field reports can give important background information for one to better understand the present situation.