Scot class, with 71 locomotives built between 1927 and 1930, and the 6P Patriot class, with 52 locomotives built between 1930 and 1934. All of the Royal Scots and 18 of the Patriots were subsequently rebuilt in line with Stanier's practice and were very successful in this form. The largest and most successful British class was the LMS Class 5 Black Five, designed by William Stanier and consisting of 842 locomotives, built between 1934 and 1951. Stanier also designed the LMS 6P Jubilee class, with 191 locomotives built between 1934 and 1936. Charles Collett of the GWR developed Churchward's 1902 Saint class design into three further classes: The GWR 4900 Hall class, with 259 locomotives built between 1928 and 1943. The GWR 6800 Grange class, with eighty locomotives built between 1936 and 1939. The GWR 7800 Manor class, with thirty locomotives built between 1938 and 1950. Frederick Hawksworth later developed the Saint class design further, first with his GWR 6959 Modified Hall Class, with 71 locomotives built between 1944 and 1950, and then with his GWR 1000 County Class, with thirty locomotives built between 1945 and 1947. The LNER inherited large numbers of locomotives from its constituent companies, many of which were subsequently rebuilt, so that the company ultimately had sixty different classes and sub-classes with this wheel arrangement. In addition, the company also introduced two new classes. The B17 class, designed by Nigel Gresley, of which 73 were built between 1928 and 1937. The B1 class, designed by Edward Thompson, of which 410 locomotives were built between 1942 and 1952. British Railways era Following the formation of British Railways in 1948, two further classes were introduced, both in 1951. The BR Standard Class 5 was based on Stanier's successful LMS Black Five of 1934. Altogether 172 locomotives were built by 1957. A lighter and less powerful design was the BR Standard Class 4. Eighty of these were built by 1957. United States The first locomotive built in the United States was the Chesapeake, built by Norris Locomotive Works for the Philadelphia and Reading railroad in March 1847. There are still conflicting opinions as to who the original designer of this type was. Many authorities attribute the design to Septimus Norris of Norris Locomotive Works, but in an 1885 paper, George E. Sellers attributes the design to John Brandt who worked for the Erie Railroad between 1842 and 1851. According