For most D.C. residents, the Potomac River is the lazy body of water that’s a little less smelly than the Anacostia, or at least clean enough to float rafts of party boats on summer Saturdays. For a history geek like Garrett Peck, who lives in Arlington, it’s the story of America: Invading armies had to cross it, construction materials for the Capitol had to travel on it, new residents had to drink from it (that was possible, once). Having exhausted his first area of expertise—the social history of alcohol, on which he’s already published three books—Peck has just finished The Potomac River: A History and Guide, an exploration of Washington’s primary waterway, all the way from West Virginia to the Chesapeake watershed. Make your next tubing trip a little more educated. Garrett Peck discusses his book at 7 p.m. at One More Page Books, 2200 N. Westmoreland St., Arlington. Free. (703) 300-9746. (Lydia DePillis)

FILM

Outdoor-movie season is almost in full effect. How do we know? Well, tonight, NoMa Summer Screen kicks off a summer of movies about the apocalypse. Yay, summer! This evening’s film: the natural-disaster flick The Day After Tomorrow. Grab a spot at Loree Grand Field starting at 7 p.m., but be sure to follow the NoMa BID’s Twitter in case the movie is canceled due to rain. 2nd and L streets NE. Free.

Artisphere is also hosting a pretty cool series at its HQ in Rosslyn: a week-long retrospective of movies by independent filmmakers Michael Galinsky and Suki Hawley, perhaps best known for their gentrification documentary Battle for Brooklyn. The married couple’s film Radiation, about a Spanish music promoter who goes on a frantic quest for much-needed cash, opens the series this evening. 8 p.m. at Artisphere’s Dome Theatre, 1101 Wilson Blvd., Arlington. $8.

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Photo by Darrow Montgomery