Here's the 1950 recipe for Can't Fail 5-Minute Fudge.
Mix 2/3 cup (small can) undiluted Carnation Evaporated Milk, 1 2/3 cups sugar and 1/2 tsp. salt in saucepan over low heat. Heat to boiling, then cook 5 minutes, stirring constantly. Remove from heat.
Add 1 1/2 cups (16 medium) diced marshmallows, 1 1/2 cups Baker's chocolate or caramel chip, 1 tsp. vanilla and 1/2 cup chopped nuts. Stir 1 - 2 minutes or until marshmallows melt. Pour into buttered 9-inch square pan. Decorate or make into roll. Or spoon into drops on waxed paper.
Makes about 2 pounds.