Architect Robert Mills was given instructions by Congress to design the building using fireproof construction material.

It was reported in the newspaper that the fire started in the room that held the patent models.

The roof was constructed of wood, which led to a rapid ignition and a fast-moving disastrous building fire.

[5] The Evening Star reported that the spectacle of the building going up in flames became extraordinarily shocking to the spectators as it turned into a calamity.

Despite the fire-proof construction efforts the fire consumed the building and devoured some 87,000 patent models with their associated documents.

Some of the important artifacts were saved, however, due to the extraordinary efforts of the Patent Office staff and some valiant firemen.

[11] There were duplicates of the drawings (a lesson learned from the first Patent Office fire in 1836) and it was just a matter of printing them again.