Put on leather glove and dig a 2-foot deep, 8-inch wide hole in the ground with post hole diggers. Use a tape measure to get the depth and circumference right while digging.
Roll a wheelbarrow next to the hole in which you are installing your Cape Cod fence post.
Put 1 part cement in the wheelbarrow, followed by 3 parts of sand. Stretch a hose from a spigot to the wheelbarrow and moisten the dry cement and sand.
Mix the cement and sand thoroughly with a mortar hoe until paste-like. Do not wet the ingredients any more or the concrete will not cure properly, becoming too weak to support the Cape Cod fence post.
Drop the Cape Cod fence post into the hole and center it inside the hole. Have someone pour the mortar mixture into the hole, around the Cape Cod fence post while you steady the post. Hold the post steady about 5 minutes once the hole is filled.
Let the concrete mortar dry for 24 hours or more before backfilling the top of the hole to cover the concrete footer with a shovel, then attaching fencing to the Cape Cod post. Repeat the same process to install other Cape Cod fence posts as necessary.