B efore fax machines, mobile phones, email and social media, sending and receiving postcards were a popular way to share moments and memories, especially for frequently traveling artists. Part of the estate of the Glass House in New Canaan, Connecticut, left by curator David Whitney and his longtime partner, Philip Johnson, the site's architect, was a box containing hundreds of postcards from artist-friends Dan Flavin, Cy Twombly, Claes Oldenberg, Robert Rauschenberg, Debbie Taylor, Jasper Johns and Andy Warhol. The famous Pop artist was a close friend of Whitney's, and between 1971–76 he sent 24 postcards with little more than a signature, leaving the images as the only clues to his active travels. The Glass House's education and interpretation manager, Kate Lichota, connects these postcard locations with Warhol's documented visits from the time. Notably, two 1971 postcards come from a particularly energetic moment for the artist in Germany, where he was promoting the premiere of Paul Morrissey's film Trash (1970), which featured many Warhol superstars, including Joe Dallesandro, Jane Forth and Holly Woodlawn.

In February 1971, Warhol sends Whitney a postcard of the grand Atlantic Hotel in Hamburg, as well as the film’s promotional postcard featuring actress Forth (a former receptionist of Warhol’s Factory) from Berlin, where the crew traveled after the premiere.

Another featuring the Swiss Appenzell Railway, sent in January 1971, suggests a trip to Zurich, possibly to create reprints of Electric Chair before his time in Germany. Initiated in 1962 at Henry Geldzahler’s encouragement to forego depictions of consumer culture and engage with more serious subject matter, Warhol’s Death and Disaster series took images of car crashes, suicides and electric chairs, as shown in newspaper images, and repeated them. Warhol famously told Artnews, “When you see a gruesome picture over and over again, it really doesn’t have any effect.” In 1971, Warhol returned to the image and experimented with colour and composition, ultimately creating ten versions of his original Electric Chair for a special portfolio.

Over the years, Warhol sent Whitney postcards dotting his travels throughout Zurich, Venice, Los Angeles, Paris, Hamburg, Berlin, Minneapolis, Tokyo, St Moritz, Marrakesh, Mexico City, Kuwait, Isfahan, Stockholm, Rome and Georgia (US). His choice of images varied – some included storied hotels, others grand landmarks, and in one case, a portrait of Pope Paul VI, signed collectively by A.W (Warhol), F.H (Fred Hughes), and B.C. (Bob Colacello).

Half of the postcards were addressed to Whitney at his New York gallery on 53 East 19th Street; the others were sent uptown to the Rockefeller Guest House, an elegantly discreet residence designed by Johnson for Blanchette Ferry Hooker Rockefeller. The couple later lived in the house for eight years beginning in 1971. Today the Modernist marvel is designated as an architectural and historic landmark, virtually unchanged from its creation in 1950. One day in September 1975, two identical postcards arrived from Minneapolis. They featured the IDS Center, a skyscraper designed by Johnson and John Burgee. Although both were addressed to Whitney, it's very likely Warhol intended them for both Whitney and Johnson, his friends.

For more of the Glass House’s collection of postcards from David Whitney's and Phillip Johnson’s estate, follow their Instagram @pjglasshouse. They share new postcards every Thursday.