Clarke supported the Prison Ship Martyrs' Monument Preservation Act (H.R. 1501; 113th Congress), a bill that would direct the Secretary of the Interior to study the suitability and feasibility of designating the Prison Ship Martyrs' Monument in Fort Greene Park in the New York City borough of Brooklyn as a unit of the National Park System (NPS). Clarke argued the bill was a good idea because "this monument commemorates not only the sacrifices of soldiers in the Revolutionary War who dedicated themselves to the cause of liberty, but a reminder that even in wartime we must protect basic human rights. These thousands of deaths were an atrocity that should never occur again."