The ingredients depended upon the tastes, traditions and prejudices of their families. Straight-laced cooks used fresh sweet cider or none at all. Others, more tolerant, used hard cider and maybe something stronger. Nowadays, here in Chicago, pie manufacturers add cheap brandy and rum to their mincemeats. The basic constituents are meat, suet, and apples.
Most recipes specify lean beef.
My folks used pork. This potent mixture was stored in a cool place at least four weeks before being used in pies. Then they celebrated Thanksgiving. Argonne National Laboratory, Division of Educational Programs, Harold Myron, Ph.D., Division Director.