On May 25, 1787, a distinguished American steps down from a carriage and beholds a stately French château. He meets the proprietor, tours the vineyards and tastes the wine. Thus begins a love affair that may well have changed the course of history. The man is Thomas Jefferson, then the official representative of the young American government in France, and the place is Château Haut-Brion. Jefferson’s visit to the famous Bordeaux estate opens a new documentary film, Eastbound Westbound, which explores how the principal drafter of the Declaration of Independence came to love the wines of Bordeaux—and how that love forged political, cultural and vinous bonds that persist to this day.

The film is co-written and narrated by Jeffrey Davies, a journalist and wine merchant who has lived in Bordeaux since the 1980s. Davies begins his journey at Haut-Brion, where he speaks with Prince Robert de Luxembourg, great-grandson of the American financier Clarence Dillon. Prince Robert shares an 1818 letter from Haut-Brion’s archives in which Jefferson discusses two of his great loves: French-American relations and, of course, wine. The letter spurs Davies to investigate the Founding Father’s passion for Bordeaux—and to seek out people who embody Jefferson’s spirit of transatlantic collaboration in the wine world today.

To that end, Davies interviews several winemakers who work in both Bordeaux and California. The impressive lineup includes Claire Villars-Lurton, of Château Haut-Bages Libéral and Sonoma’s Acaibo; Alfred Tesseron, of Château Pontet-Canet and Napa’s Pym-Rae; and Denise Adams, of Château Fonplégade and Napa’s Adamvs.

The winemakers and their families carry on a tradition of closeness between France and the United States—one that, the film shows, has been partly facilitated by wine. Since at least the days of Jefferson, wine has fostered connections between the two countries in politics, culture, the arts, economics and more. France is the United States’ oldest ally; the allegiance officially dates to 1778, and French support was crucial to the United States winning independence from Great Britain. Bordeaux was home to the first overseas American consulate, and as Prince Robert says in the film, “Bordeaux has always been about reaching out across borders … Bordeaux means ‘on the edge of the water,’ and the water as we knew it was the motorway of the world.”