Where did the name sugarloaf come from and what is a sugarloaf?

In the old days 60 years ago, there wasn't so much plastic trash everywhere. People bought loaves of salt and loaves of sugar. You've seen a loaf of bread. A sugar loaf is the same size as that. It's just a big lump, cake, or loaf of sugar. You rub it and the little crystals fall off.