Good early 1900s vintage square glass jar, one gallon size (embossed 4 qt on the side). This was made as a canister, I think - though it's about the size and shape of a churn jar.
It measures 6" x 6" at the base, 7 3/4" tall to the shoulder, 9 1/2" tall overall. There's a tiny chip to the rim, not at all visible with the metal lid in place.