Question: Are Kenneth Clark and William March both British?

Context articles: Mamie Phipps Clark
Saltwood Castle
George Hooper (artist)
What is a Masterpiece?
Independent Television Authority
William March
Kenneth Clark
Kenneth and Mamie Clark
Classicism
The Two Worlds of William March

Mamie Phipps Clark was an American social psychologist that focused on the development of self-consciousness of pre-schooled black children, along with her husband Kenneth Clark.
 Clark was born and raised in Hot Springs, Arkansas in 1917.
 Clark received her post-secondary school, schooling at Howard University and earned a bachelor's and master's degrees there.
Saltwood Castle is a castle in Saltwood village, one mile (2 km) north of Hythe, Kent, England.
 Of 11th century origin, the castle was expanded in the 13th and 14th centuries.
 After the Norman Conquest, the castle was appropriated by the Archbishop of Canterbury Lanfranc and remained the property of the archbishops, with some interruptions, until 1540, when Thomas Cranmer was compelled to cede it to Henry VIII.
 The castle is reputed to have been the meeting place of the four knights who carried out the assassination of Thomas Becket in 1170.
 By the 19th century, it was "largely ruinous" and restorations to make portions of the castle habitable were carried out in the 1880s and 1930s.
 In the late 19th century, the castle was bought by an ancestor of Bill Deedes, the journalist and politician, who grew up there.
 In the 20th century, it was sold to Sir Martin Conway who commissioned Philip Tilden to undertake a restoration.
 In 1953, the castle was bought by the art historian Kenneth Clark (1903–1983), and then became the home of his son, the politician and diarist, Alan Clark (1928–1999).
 It remains the private home of his widow, Jane Clark.
 The castle is a Grade I listed building.
George Hooper was a British artist who worked in a unique style informed by Fauvism and the Bloomsbury Group although his style varied greatly throughout his long career.
 Hooper was born on 10 September 1910 in Gorakphur, India and died on 18 July 1994 in Surrey, England.
 During World War II He was invited to join Kenneth Clark’s Recording Britain scheme as one of a small group of artists commissioned to create works that would, “...boost morale by celebrating the country’s natural beauty and architectural heritage”.
 He taught at Brighton College of Art and works of his are in the Victoria and Albert Museum, The British Museum and a number of smaller galleries in Sussex.
 He spent most of his later life in Redhill in Surrey painting largely independently of any school or group of artists.
 He married Joyce Katherine Hooper MBE (who later founded Surrey Opera) in 1941.
What is a Masterpiece?
 is a 1979 non-fiction book by British historian Kenneth Clark.
 It is a transcribed version of the Walter Neurath memorial lectures given by Clark.
 The work, initially released on 1 January 1979, received a Thames & Hudson republication on 1 May 1992.
The Independent Television Authority (ITA) is a defunct agency created by the Television Act 1954 to supervise the creation of "Independent Television" (ITV), the first commercial television network in the United Kingdom.
 The ITA was responsible for determining the location, constructing, building, and operating the transmission stations used by the ITV network, as well as determining the franchise areas and awarding the franchises for each regional commercial broadcaster.
 The Authority began its operations on 4 August 1954, a mere four days after the Television Act received Royal Assent, under the Chairmanship of Sir Kenneth Clark.
 The Authority's first Director General, Sir Robert Fraser was appointed by Clark a month later on 14 September.
William March (September 18, 1893 – May 15, 1954) was an American writer of psychological fiction and a highly decorated US Marine.
 The author of six novels and four short-story collections, March was praised by critics but never attained great popularity.
Kenneth Mackenzie Clark, Baron Clark, (13 July 1903 – 21 May 1983) was a British art historian, museum director, and broadcaster.
 After running two important art galleries in the 1930s and 1940s, he came to wider public notice on television, presenting a succession of series about the arts during the 1950s and 1960s, culminating in the series "Civilisation" in 1969.
Kenneth Bancroft Clark (July 14, 1914 – May 1, 2005) and Mamie Phipps Clark (April 18, 1917 – August 11, 1983) were African-American psychologists who as a married team conducted important research among children and were active in the Civil Rights Movement.
 They founded the Northside Center for Child Development in Harlem and the organization Harlem Youth Opportunities Unlimited (HARYOU).
 Kenneth Clark also was an educator and professor at City College of New York, and first black president of the American Psychological Association.
Classicism, in the arts, refers generally to a high regard for a classical period, classical antiquity in the Western tradition, as setting standards for taste which the classicists seek to emulate.
 The art of classicism typically seeks to be formal and restrained: of the "Discobolus" Sir Kenneth Clark observed, "if we object to his restraint and compression we are simply objecting to the classicism of classic art.
 A violent emphasis or a sudden acceleration of rhythmic movement would have destroyed those qualities of balance and completeness through which it retained until the present century its position of authority in the restricted repertoire of visual images."
 Classicism, as Clark noted, implies a canon of widely accepted ideal forms, whether in the Western canon that he was examining in "The Nude" (1956), or the literary Chinese classics or Chinese art, where the revival of classic styles is also a recurring feature.
The Two Worlds of William March is a 1984 biography of William March, written by the British scholar, critic and author Roy S. Simmonds.
 William Butcher, reviewing the biography for "World Literature Today", called it "a judicious record of March's life and a fine tribute to his literary achievement".