In Salem, Lard is being used as Mortar. I know I'm sort of slow in finding this out but I didn't particularly care about making a wall, I was busy with exploring all the new foods.
Lard HAS been used in Mortar, but its very ****** mortar. Its bad enough that lime is used for mortar, lime based mortar was one of the worst in history and extremely brittle. Now there are 2 reasons this rustles my jimmies big time, first is, lard being used in Mortar sounds incredibly retarded. The second one is that its ****** Mortar.
Now, you'll ask "But what else could've been used instead of lard that's also in the game?"
There's quite the easy answer for this. Eggs. Egg whites were used in making Mortar, around that time, and even in the 1900's still. A ton of eggs as a substitute for lard in making Brickwalls would not only result in better mortar, but also not require you to farm a thousand lard just to make a wall. Lard needed in enough other things already while Eggs are barely used for anything, and aren't nearly as hard to raise in the thousands.