[3] It was nominated for its association with Traphagen, recognized together with his business partner Francis W. Fitzpatrick as Duluth's leading architects of the late 19th century.

The main façade is built of local red sandstone and features ornate carving and window dressing, along with towers and unusual dormers.

A wraparound front porch spans the width of the ground floor, with stone balustrades marking the corners over the two entrances.

[2] The Traphagen House was originally designed as a duplex with two separate entrances and very similar floor plans on either side, with the exception of the front windows.

He'd moved to the city in the early 1880s with his brothers George and Walter, after a childhood in New York and a few years in Saint Paul, Minnesota, where he'd worked as a carpenter.

Partnering with Francis W. Fitzpatrick brought additional renown, as their firm produced designs for several prominent buildings in Duluth.

[2] Oliver Traphagen sold the house to mining magnate Chester Congdon, who lived there with his family from 1897 until their mansion Glensheen was completed in 1908.

Duluth firefighters extinguished the blaze, but what owner Howard Klatzky described as "the fanciest part of the whole building" was profoundly damaged, and the exterior was blackened on that side.

[8] In the morning the owner of a business across the street found a Molotov cocktail that had been thrown through his basement window but failed to ignite.

[10] The fire in the Traphagen House struck just as the tenant businesses were about to relocate to more modern facilities in the DeWitt–Seitz Building in Duluth's Canal Park.