Continuing his epic Californian rail journey, Michael Portillo begins this leg at the very spot that triggered the 1848 gold rush. He finds out how California's mineral treasures and population swell helped fast-track the region's statehood, with significant political consequences for the national slavery battle. Michael pans for gold in the clear waters of the American River, and delights in a titillating spectacle at California's first public theatre.

Venturing underground, he discovers how the streets of Sacramento were raised following the Great Flood of 1862 and visits the newly

constructed $900 million dam to improve the city's flood defences. It is a first for Michael in the kaleidoscopic sweet factory of an iconic American confectionary brand that can trace its roots back to the 19th century. And, taking a cue from his guidebook, he explores the fruits of the Napa Valley enjoying a gourmet lunch on board the Napa Valley wine train before joining the harvest of the state's distinctive Zinfandel grape.