According to a crochet pattern published by the Spool Cotton Company in 1941, "the thrifty womenfolk of our early American days carefully saved odds and ends of yarn, leftover colors, ravellings from sweaters and socks all to be made into a robe for the family’s general use.
As fast as the yarn accumulated, it was crocheted into small squares the colors tastefully combined from whatever yarn was available at the time. When sufficient squares were completed, they were sewed together to make a colorful blanket useful for many purposes as a bedspread, for a shawl, as a leg and lap covering, for sleighing, for bundling, as a throw over a rocking chair, and a colorful decoration around the house.
Because grandmother played the major role in its making, the robe was affectionately called the Granny.
Because granny’s robe originally was made of many colors, it resembled a particular type of colorful rug brought from Afghanistan to this country by the gallant sailing ships of colonial times. So the nickname, Afghan, came into popular use!
Today, Afghan is used to describe various kinds of robes and blankets which are crocheted or knitted of soft wool yarns in the beautiful shades suggested by style and made available by modern thread and yarn manufacturers."