Leaving Wales in 1873 with his father for the United States, Harris was next known to be in the Washington, D.C., area in 1890 when he was enrolled in the Arlington Academy, a private secondary school.

He left the academy without graduating in 1893 and moved to Chicago, to design residential buildings under Henry Ives Cobb.

[c] He worked another seven years for Hornblower & Marshall as a junior architect and supervised the construction of the Army and Navy Club.

One exception was a 1931 addition to the Park View School, designed in 1916 by Snowden Ashford, where Harris followed the original Gothic Revival style.

For example, the Janney Elementary School was constructed in 1925 with the main core containing a library and administrative space, an academic east wing, and a gymnasium and auditorium in the rear.

This plan was used six times, including the Twin Oaks Playground and Field House, which is listed on the NRHP and the Mitchell Park Field House, a District of Columbia Inventory of Historic Site and as of 2019[update], submitted for listing on the NRHP.

However, years of trouble slowed Harris's plans as numerous battles with the federal government and Commission of Fine Arts erupted over various issues, including funding and cost, the specific site of buildings.

Along with his staff at the Office of the Municipal Architect, Harris continued to work through these issues and design the campus, until he died suddenly in February 1933.

[11] Harris was said to have an "excellent working relationship" with the Fine Arts Commission, due to his willingness to design buildings in their preferred Colonial Revival style.

"[5] They also praised his willingness to utilize private architects, primarily for elementary schools, to augment the city staff during the construction boom in the 1920.

A high standard has been achieved, both in plan and design, with the result that the Washington school buildings are equaled by few and excelled by none.

The sympathetic attitude displayed by Mr. Harris together with sound advice, has been of great assistance to the Board of Education.

[2] While employed by Hornblower & Marshall, he was involved with the following projects:[3] From 1921 to 1933, Harris is credited as architect of the following municipal structures: