The fashions in the way things were knit is interesting. The 1908 sweater I knit was knit with the body in one piece back and then front but separate sleeves. By the early 1920's there are all these sweaters knit in one piece, again back to front, this time including the sleeves. Then in the early 1930's there are a bunch of sweaters knit in one piece, but this time in the round starting at the neck. By the 1940's they mostly seem to be knit in separate pieces for front, back, and sleeves.

I'm definitely fondest of the 1940's method, partly because I live in a hot place and partly because I like to be able to carry my knitting in my lunchbox. A whole sweater doesn't fit all that well in my lunchbox.