 During 1919, Pliny Holt returned to Stockton and the Holt company where the "Mark VII" was designed and built. It had a 75 millimetres (3.0 in) gun mounted and ran at a top speed of 18 miles per hour (29 km / h). In 1921, the company finished the "Mark VI", which achieved speeds of up to 31 miles per hour (50 km / h) on a test run from Stockton to San Francisco and back.
