In the mid-19th century, the grape phylloxera, a tiny aphid, began ravaging vineyards across Europe. 40% of France’s vines were killed in 15 years. Then (as many times since), the US to the rescue:
Then someone realized that if you grafted European vines onto American roots, you got vines that could successfully resist phylloxera. The question was whether they produced wine as good as they had before.
In France, many vineyard owners couldn’t bear the thought of corrupting their vines with American stock. Burgundy, fearful that its beloved and exceedingly valuable grand cru wines would be irreparably compromised, refused for fourteen years to allow American roots to besmirch its ancient vines, even though those vines were puckering and dying on every hillside. Many growers almost certainly engaged in a bit if illicit grafting anyway, which may have saved their noble wines from extinction.
But it is thanks to American roots that French wines still exist.
(Bryson, At Home: A Short History of Private Life)