Beginning of last Century socks were still made on flat linear machines. There were two kind of problems : the first was the sock had to be cut and then linked on the back in order to have a tubolar and the second was there was no elastic and socks had to be worn with garters.
Furthermore it was a long and extremly slow process to have the final product.
Around the '30 on the market arrived the first English machines capable to do the socks as we see today.
The tale is actually more complicated, but we will have time in the future to talk another time about it.
Attached couple of pictures of '50 sock.