Harriet Abigail Morrison Irwin (1828-1897) was the first woman architect to patent an architectural plan for a house. The patent, entered in 1869, was a design for a hexagonal house. She used her plan to design and build her house which was located at 912 W. 5th Street in Charlotte. She built at least two other houses in Charlotte. These two houses were built using more conventional designs.

Harriet Irwin was the daughter of the Reverend Robert Hall Morrison, the first president of Davidson College. She was married to James P. Irwin of Mobile, Alabama. Though starting married life in Alabama, the couple soon returned to the Charlotte where they remained. The Irwins had nine children.