1859, the new building was complete. Supervised by warden Capt. Thomas C. James, the new jail had three hundred cells in two separate wings. The Sun observed: "Baltimore can now boast of a prison in point of appearance, stability and comfort, second to none other in the country."

Despite the physical improvements, the jail remained dedicated to an awful purpose. From 1859 to 1864, the Baltimore Jail was used to hold hundreds of “runaways” along with Marylanders, both white and Black, who assisted enslaved people as they fled to freedom. At the time, a number of private slave jails operated around the harbor but, for a fee, slaveholders could also leave the men and women they held at the city jail.

The buildings where these men and women were heldremained almost unchanged for a century until they were transformed in the 1960s. The Warden's House is one of the only jail buildings that has been preserved. The gateway had long since been converted into the warden's living room. In 1974, converted into offices while keeping the building's distinctive interior intact.

At present, change is coming to the Baltimore Jail once again; threatening the Warden's House and the nearby 1898 Maryland Penitentiary with demolition. In July 2015, Governor Larry Hogan announced the immediate closure Baltimore jail following years of concerns and controversy over conditions for inmates and corrections officers. In the spring of 2016, the Maryland Division of Corrections (MDC) released their preliminary plan for the demolition of the Baltimore City Detention Center including this local landmark. Planning is