With a steadily growing population, the federal government agreed to construct a building in North Bay that would host a post office and other federal offices. Lot #108 on the north side of Main Street, at Fraser, was purchased by the crown from the William Doran family for $8,000 in 1905. The federal building cost $50,000 to construct and opened for business in 1908.

The post office was a two-story masonry structure of dark red brick, concrete, and stone, set on a foundation of rough-faced stone blocks. A set of stone steps led to the Main Street entrance, which had over-sized oak doors with a half rose window within a roman arch. The entrance was flanked on each side by a huge stone pedestal base supporting double columns. A simplified Corinthian capitol and a pediment bearing the recessed wording “Post Office” were other detailed features of the entrance. Other building details included the keystone surrounds on the first floor windows, and a roofline that featured a cornice, a stone/concrete balustrade, and a prominent pediment. The first floor interior had oiled hardwood flooring and on one side of the lobby was a row of wickets with brass grills.

A constant focus of post cards, the somewhat grandiose post office building was easily the most outstanding, non-religious structure in the area. The building was called “the nerve centre of business activity in the city,” and it became the headquarters for a number of drives to help the war effort during the Second World War.

The building was closed in 1957 and demolished the following year. In 1957, the property was sold to S.S. Kresge, the present structure was constructed, and Kresge’s store operated at the site until the 1980s. In 1990, K Mart Canada sold the building. The cornerstone for a new federal building (at the corner of Ferguson and Worthington) was laid in 1956. This new site is still the main post office for the district.