Cut the potatoes into dice and chop the eggs fine. Chop the onions, or slice them very thin. Sprinkle the potatoes, eggs and onions with the salt and pepper, and mix thoroughly. Pour the oil gradually over the mixture, stirring and tossing continually; lastly, mix with the other ingredients the vinegar, in which the sugar has been dissolved. Sprinkle chopped parsley over the top.
Attributed to Carrie M. Dearborn.