Designed by Frederick and Edward Baumann, it was built between 1873 and 1874 in the aftermath of the Great Chicago Fire of 1871.

[1] The building has limestone facades and originally included an exterior staircase that led to a second-floor corner entrance.

[4] The building was originally intended to host upscale offices for companies wanting to be close to the nearby then-blossoming LaSalle Street financial district.

[2] During the mid-1900s, the owner hammered off ground-level architectural details in order to modernize the storefronts.

[2] The Washington Block's foundation enabled it to be built on soft, compressible soil, instead of the solid bedrock formerly seen as a requirement.