Built in 1903 of common bond brick, the D building was the fourth so-called residential "cottage" for female residents of the hospital. Originally there were three buildings, but with the rapid expansion of the hospital population, it became necessary to build more. The D building was the first of these newer buildings. 

The idea was that rather than grouping all the patients in a single giant building, patients would live in smaller buildings, which were referred to as "cottages." Although originally it was named just "The Womens' Group," the complex (sometimes referred to as a colony) where the women lived was later named the Warfield Complex after Maryland Governor Edwin Warfield, who served from 1904 to 1908. 

(Although Wade Warfield was an influential local businessman and politician, and a member of the hospital's board of managers, the complex is not named in his honor.)

The complex is now part of the town of Sykesville, but the town does not own the buildings. They sold them and the land to a developer in 2018. The developer has done nothing to develop the cottages and the D building is crumbling, at least its exterior, and certainly the front entrance.