But making things out of crocheted squares evidently goes back further than the 1970s. There is a very nice example in the Knitting & Crochet Guild collection - a stole with fringed ends.
We didn't have a date for it, but then just last week we identified it in Vogue Knitting No. 47, published in Autumn 1955. The magazine give this description: "Tile motif in bright hues brings crochet up-to-date for a heavenly stole-of-many-colours." Garments made from granny squares often have a folksy, hippy look, but this one is very elegant.
The pattern specifies 3-ply wool, so that it's quite delicate - the squares are only 1¾ inches wide (about 4.5 cm.) You might expect a Vogue Knitting pattern to suggest the colours to use, but it just lists 8 oz. (225g.) of a background colour and about 9 oz. (255g.) of 'various colours for the medallions'. As you can see from the detail, our example is very well-made - the squares are joined together very neatly. And it has a long plaited fringe, following the pattern instructions. (The fringe takes 7 oz. (200g.) of wool by itself.)
It's very satisfying when we can match up a piece in the collection and a pattern - even more so when the pattern is from Vogue Knitting, and gives us a slightly unexpected date for the piece.
One other question: I'm sure that we didn't call them granny squares in the 1970s, at least not in this country. When did we start using that name? And where did it come from?