The 1960s saw many fashion battles—pants, pantsuits, miniskirts, etc. But when I was growing up at the time, I thought the biggest showdown was between the sheath dress (modern) and the shirtwaist (not). Imagine my surprise to see versions of these two silhouettes shown as equivalents in the Sears catalog, mid-sixties. I know that the slim skirted version above was not a true sheath dress, since it buttoned to the waist like its fuller counterpart. But its trim style still looks modern to me next to the full skirted cousin.
Note that both versions are sold in half sizes, a category that indicates “not quite cutting edge.” In the same catalog the clothes for juniors look quite different—shorter, sleeker, more fluid. And there is nary a gathered skirt to be found.