Fort Reno, located eight miles downstream (northeast) from Sussex on the Powder River, was built in 1865 as one in a series of military posts to protect travelers on the Bozeman Trail.

In 1877, Cantonment Reno, five miles downstream from Sussex, was established as a supply depot for the Powder River Campaign of 1876.

The active freight route along the Bozeman Trail that connected the military outposts between Cheyenne and Buffalo developed into roads, and Sussex became a stop along the way.

[3] In 1914, the same year the bridge was completed, Leitner erected a new building to house the post office, store, and dance hall.

The long rectangular building is unadorned except for simple knee braces and brackets under the wide overhanging eaves, corner boards, and plain window surrounds.

In the late 1920s, the store and post office moved to a renovated garage east of the present building, and the entire room became devoted to a dance hall/community center.

In the early 1950s, the lean-to on the north side where dinners were served collapsed and the floor needed replacing after many years of hard use.

The outhouse and vestibule received modifications, wood paneling was placed on the interior walls, and a drop ceiling installed.

[1] The Sussex Community Hall was an active place for many years, hosting such varied activities as Halloween, Christmas and Thanksgiving suppers, Mother-Daughter banquets; "harvest suppers"; wedding receptions; picnics and barbecues; home-talent plays; school programs, and annual meetings of the Sussex Irrigation Company.