James McNeill Whistler moved from Paris to London in 1859, and over the next four decades, the River Thames featured prominently in his work. In river scenes such as Thames Police and Black Lion Wharf, Whistler skillfully showed both nature and human activity in the gritty, industrial docklands of London in an area known as Wapping. Ships, patrol boats, wharves, and warehouses are depicted in detail, while river laborers and navigators, known as watermen, are shown at work and rest. In 1859, the year these works were created, ownership of and access to the river was under debate. Watermen, represented by their guild, fought against the Board of Trade, which aimed to restrict access to the Thames and impose new taxes on commercial transit. During this period, pollution and overcrowding of the River Thames were of great public concern, eventually leading to massive civil engineering projects that dictated how the river was used.