Having visited several hundred prisons across England, Scotland, Wales and wider Europe, Howard published the first edition of "The State of the Prisons" in 1777. It included very detailed accounts of the prisons he had visited, including plans and maps, together with detailed instructions on the necessary improvements, especially regarding hygiene and cleanliness, the lack of which was causing many deaths. It is this work that has been credited as establishing the practice of single-celling in the United Kingdom and, by extension, in the United States. The following account, of the Bridewell at Abingdon, Oxfordshire, is typical: