You can drive through parts of the South and see entire landscapes covered in this vine. The big mounds you see out there; what do you think they are? Well, they used to be trees. Nice, big, healthy trees.
As Option8 has indicated, kudzu (Latin name Pueraria lobata) was imported to the US willingly. The Japanese delegates to the US displayed the vine in 1876 as "kuzu." In 1884, it had become known as kudzu and was shown at the New Orleans Exposition. Soon thereafter, it was widely planted in the South as a cheap source of food for grazing livestock as well as an erosion-control agent.
The real problem began in the 1940's when the CCC (Civilian Conservation Corps run by the Federal Government ("We're only here to help you.")) began planting it in ditches along highways.
The vines can grow 12 to 18 inches a day. Unlike most plants, they grow at night by storing energy during the day and using it when it's dark. Roots can grow 20 feet down. Some plants have been known to grow a total of 100 feet a year. It can grow almost anywhere, even across areas where hardly any other plant could survive. Anything not watched carefully can be covered in kudzu within days. Not only trees, but barns, houses, swimming pools, etc. Police often discover bodies underneath the kudzu in the winter when the foliage falls off the vines. It has saved some lives by cushioning the crash of cars which run off the road.
It was 1972 before the USDA declared it a noxious weed and plans were made to stop its spread. Unfortunately, nothing can kill it. You can burn it, pour herbicides on it, even spray it with Agent Orange. It all seems to just make it grow back stronger. Kudzu now covers 7 million acres from Florida to New York and Texas. Alabama, Georgia and Mississippi have the heaviest infestation. (Thanks a lot, FDR!)
A new fungus has been developed (Myrothecium verrucaria) and this may just work to eradicate the devil weed. Let's see what the tree-huggers have to say about this, eh? Which is more valuable, a weed or a tree? Who draws this ecological line in the sand?