There, he was able to establish the usefulness of the spiral-shaped Frank Lloyd Wright-designed Guggenheim as a venue for the display of art, despite the doubts of critics and artists.

[5] After working as a multilingual monitor and interrogator for military intelligence at the Office of War Information in New York, he enlisted in the U.S. Army and became a U.S. citizen in 1944, seeing combat overseas in 1944–1945.

[2][6] After the war, Messer worked at the Office of Military Government, United States in Munich, Germany, studying art for the first time at the Sorbonne in Paris.

[3] Three-dimensional sculpture, in particular, entailed, "the problem of installing such a show in a museum bearing so close a resemblance to the circular geography of hell," where any vertical object appears tilted in a "drunken lurch" because the slope of the floor and the curvature of the walls could combine to produce vexing optical illusions.

"[3] Messer had the foresight to prepare by staging a smaller sculpture exhibition the previous year, in which he discovered how to compensate for the space's weird geometry by constructing special plinths at a particular angle, so the pieces were not at a true vertical yet appeared to be so.

[4] In the earlier sculpture show, this trick proved impossible for one piece, an Alexander Calder mobile whose wire inevitably hung at a true plumb vertical, "suggesting hallucination" in the disorienting context of the tilted floor.

[10] At Messer's urging, in 1976, Peggy Guggenheim donated her art collection and home in Venice, Italy, the Palazzo Venier dei Leoni, to the foundation.

At the exhibition put on in celebration, "virtually every foreign artist who has ever shown at the Guggenheim flew in to pay tribute" to Messer.