Milwaukee Road class F7
The F7s are major contenders for the fastest steam locomotives ever built, as they ran at over daily. One run in January 1941 recorded by a reporter for "Trains" magazine saw achieved twice—in the midst of a heavy snowstorm. Baron Gérard Vuillet, a French railroading expert, once recorded a run between Chicago and Milwaukee where the locomotive reached and sustained an average for . However, the British locomotive LNER Class A4 4468 "Mallard" is officially accepted to be the world's fastest, with a run recorded at but authenticated at 126 mph in 1938.
San Francisco and San Jose Railroad
The first full-sized steam locomotive produced in the state of California was built for the SF&SJ by the Union Iron Works in San Francisco. It was appropriately named the "California". Its inaugural run was August 30, 1865, during which it set a speed record of . Union Iron works also built a similar 28-ton locomotive number 7 and the 18-ton switcher number 8 in 1865. Norris built two more SF&SJ locomotives weighing 26 tons and 28 tons in 1867, while McKay and Aldus of Boston built two 30-ton locomotives. Rhode Island Locomotive Works built a 30-ton locomotive for SF&SJ in 1868, as did Cooke; and Schenectady Locomotive Works built two more. 1870 brought another 30-ton locomotive from Mason and two 33-ton locomotives from Cooke.