O'Neill Building
On the death of Hugh O'Neill in 1902, his heirs were unable to continue running the business, which was sold and merged in 1907 with the Adams Dry Goods Store immediately to the north at 675 Sixth Avenue. The combined business did not succeed and, like all the department stores in the Ladies' Mile, was gone by the advent of World War I. The building was converted to manufacturing lofts, and then back into offices around 1969. As of 2014, the building is owned by ElAd Properties, and was converted into condominiums in 2005.
On Christmas Day 2012 the building suffered a partial collapse of its facade and was evacuated.
The O'Neill Building is part of the Ladies' Mile Historic District, which was created by the New York City Landmarks Preservation Commission in 1989. In its designation report, the Commission wrote "Because of its architecture and history, the Hugh O'Neill Building is one of the department store buildings which give the Ladies Mile Historic District its special character."