The Harden Nowlin House is actually located at the rear of 614 Washington Street. The small, one-story, white building was for a time the home of a politician who played a part in the early government of both Wisconsin and Iowa.

Harden Nowlin was born in Illinois in 1804. He moved to Galena in 1825 to work in the mining business there. When the Iowa side of the Mississippi River was opened to settlement, he moved to Dubuque, where his daughter, Mary, was born in 1836.

What is now Iowa was then part of the new Wisconsin Territory. Nowlin was chosen as a member of the first Wisconsin territorial legislature, a service he later repeated when the separate Iowa Territory was formed in 1838. This first legislature met in a temporary capitol in Burlington. Nowlin served in the legislature that made the decision to establish a permanent capital to Iowa City.

The Harden Nowlin House was built in the early 1860s and purchased by Nowlin in 1871. Nowlin and his wife, Martha, sold the house to their daughter, Mary, in 1885. After Nowlin's death in 1892 the house was sold to Nellie Strayer, who built the apartment in front and moved the house to its present location.

Nowlin's daughter, Mary, is remembered for reasons other than politics. She married H. B. Allen, an attorney from New York, in 1857. Waterloo's Allen Memorial Hospital was named in her memory.