The Airedale Foundry built nearly 6,000 locomotives for use in Britain and abroad from when it was founded until the end of the 19th century. The company diversified into manufacturing stationary engines for agricultural use and steam engines for tramways. From the 1880s, the Monkbridge works made steel using the Siemens–Martin open-hearth process. The Airedale Foundry and Monkbridge Works both employed about 2000 workers in 1911. In connection with his business interests Kitson was a member of the Institution of Mechanical Engineers from 1859 and was president of the Iron Trade Association. He was president of the Iron and Steel Institute in 1889 and was awarded the institute's Bessemer gold medal in 1903. Between 1899 and 1901, he was a member of the council of the Institution of Civil Engineers. Kitson's other interests included the London and Northern Steamship Company, the Yorkshire Banking Company. He was a director of the London City and Midland Bank and president of the Baku Russian Petroleum Company. He was also a director of the North Eastern Railway Company. He was president of the Leeds Chamber of Commerce from 1880 to 1881. Financial success allowed Kitson time, money and influence to pursue other interests including politics. He was President of the Leeds Liberal Association, and ran the election campaign for William Ewart Gladstone. In 1880, Kitson was a committee member of the Leeds Trained Nurses Institution. He was MP for Colne Valley from 1892 until 1907, supporting education, Irish Home Rule, and old age pensions. Kitson was a member of the Institution of Civil Engineers and the Institution of Mechanical Engineers. He supported the Mechanics' Institute and the Yorkshire College, the forerunner of the University of Leeds, which awarded him an honorary doctorate, DSc in 1904. Kitson was never a member of Leeds Council but was the city's first lord mayor in 1896–7. He was created a baronet in 1886 and was sworn of the Privy Council in 1906. On 17 July 1907 Kitson was raised to the peerage as the first Baron Airedale, of Gledhow in the West Riding of the County of York. Airedale died following a heart attack in Paris at the Hotel Meurice on 16 March 1911. He had been returning home by train from the south of France. His funeral service was held at Mill Hill Chapel on 22 March before his body was taken for burial to Roundhay Church along a route lined by 4000 workpeople.